Thursday, December 31, 2015

Tonight's Sky for December 31: Get Sirius for the New Year

Ring in the New Year with Sirius, alpha (brightest) star of Canis Major, the big dog, and brightest star in the entire sky. Why the New Year connection? Sirius is very near to due South on New Year's Eve. To see it, go out at midnight and look South to find an extremely bright blue star, Sirius. 

Wednesday, December 30, 2015

Tonight's Sky for December 30: Venus Rises 3 Hours Before the Sun

This morning, Venus, second planet from the Sun and third brightest object in the night sky, will be rising 3 hours before the Sun. Now, while not as early as the 4 hours before the Sun rise that was taking place last month, any morning planet rising 3 hours before the Sun mean t hat it will still be pretty high come the predawn hour. 

Tuesday, December 29, 2015

Tonight's Sky for December 29: Mercury at its Best


Want to join a small club of people who have seen the planet Mercury? Well, here's your chance as the first planet from the Sun has reached a point in its orbit called greatest elongation, which is a fancy way of saying that, as seen from Earth, Mercury is as far from the Sun as it will get on this orbit, which is crucial for observing as, of all the Classical Planets (those known to the Ancient Greeks and Romans), Mercury is by far the hardest to spot because, as seen from Earth, it spends a lot of time obscured from view by the Sun's glare.


So, take a moment or two, go out just after sunset, and try to spot Mercury. If you are successful in spotting the speedy planet, you are accomplishing something that the great astronomer Nicolaus Copernicus (who rediscovered the idea of a sun-centered solar system) supposedly never did. 

Monday, December 28, 2015

Tonight's Sky for December 28: Orion Due South at Midnight

Tonight, Orion, king of the winter sky, is due South at midnight. For anyone just getting into astronomy who wants to see one of the most famous constellations in the sky, here's a perfect opportunity to do do.

Sunday, December 27, 2015

Tonight's Sky for December 27: Johannes Kepler Born (1571)


It was on this date that Johannes Kepler was born. Initially sent to a seminary to become a member of the Lutheran Clergy, Kepler instead found a love for mathematics, which became his first profession when he took a job as a math teacher. While a teacher, Kepler wrote a book on astronomy, specifically planetary orbits. This work attracted the attention of many astronomers, including Tycho Brahe, the greatest of the pre-telescopic astronomers, who invited Kepler to join his staff.

The relationship between the two men was awkward. Brahe was an astronomer, not a mathemitician, and he knew that he needed Kepler's mathematical genius to make sense of his volumes upon volumes of data. At the same time, Kepler knew he needed Brahe's data if he were to make any discoveries about planetary orbits. Unfortunately for Kepler, Brahe regarded his observational data as his life's work and wasn't about to start giving it out freely. Between the time he joined Brahe's staff in 1599 to the time Brae died in 1601, Kepler almost quit his position several times over frustration about not being granted access to the volumes of data Brahe had compiled in over 30 years of observations.
After Brahe died, though, Kepler would be appointed to Brahe's position of Imperial Mathemitician, which thus granted Kepler access to all of Brahe's data.

Eagerly plunging into his work, Kepler immediately came across problems, specifically that the observational data could not be reconciled with planets having a circular orbit, as proposed by Copernicus. In the time that followed, Kepler tried various models for planetary movement in the hope of finding one that would fit the observations. Try as he might, Kepler just couldn't reconcile the models to the observations, especially in regards to the planet Mars, which exhibited the greatest irregularity in its orbit.. Finally, in desperation, Kepler, a deeply religious man who sought to find proof of a divine blueprint for the solar system, gave up the perfect circles that had so dominated astronomy for centuries. Upon calculating the orbits of the planets as ellipses (slightly elongated circles) the observation and theory finally agreed. It was this discovery that planets' orbits ere elliptical that inspired Kepler's 3 laws of planetary motion.
Law 1: All planets move in elliptical orbits with the Sun at one of the foci.
Law 2: All planets move through equal areas of space in equal times ()basically, planets move faster when closer to the Sun and slower when farther away).

Law 3: A planet's period of orbit is proportional to its distance (orbital period (in years) of the planet squared equals the semimajor axis (in AU) cubed). This discovery showed that there was some common force governing planetary motion (this force is gravity, but Kepler didn't know this yet).



Unfortunately, try as he might, Kepler, while he could explain “hows” of planetary motion, he couldn't explain the “whys.” This task would occupy him for the rest of his life until 1630.

Saturday, December 26, 2015

Tonight's Sky for December 26: Mary Somerville is Born (1780)

It was on this date in 1780 that Mary Somerville, one of the first women to become famous in the field of astronomy, was born.

Somerville's tale is one of struggle against adversity. At the time, girls were not only often denied access to an education, but were often discouraged from seeking one. Mary's situation was no different and her parents even blamed her quest for knowledge for the death of her own sister! While giving up on formal education and taking the societal path of a well-connected lady (her father was a doctor), Mary continued to study in secret and, with the inheritance she got upon the death of her husband, she was free to pursue intellectual interests, with the support of her second husband, eventually becoming known as both a writer and translator.


She was also one of the first women to be inducted into the Royal Astronomical Society, which she achieved in 1835, the same year that Caroline Herschel, William Herschel's sister and assistant, received the same honor. In 1868, Somerville was awarded the Victoria Cross of the Royal Geographical Society.

Somerville died in 1871, aged 91.

Friday, December 25, 2015

Tonight's Sky for December 25: Full Moon

Tonight, the Moon will reach its full phase, which means that, as seen from Earth, it is directly opposite the Sun in the sky as seen from Earth and is at the half way point in its current orbit.


As for lunar mechanics, the Moon is always half lit. The reason we don't always see it as such is thanks to orientation in relation to us. Right now, when the Moon is opposite the Sun and on the far side of Earth, we can see all of its lit side, which is why it appears to be “full.” In the coming nights, we will start to see less of the Moon as its lit side starts to turn away from us as seen from Earth and heads toward Third Quarter. 

Tuesday, December 22, 2015

Tonight's Sky for December 24: Apollo 8 Reaches the Moon, Christmas Broadcast

It was on this date that Apollo 8 reached the Moon, becoming the first manned mission to enter into lunar orbit. In addition, this mission featured the famous Christmas Eve Broadcast. Rather than describe this, here's the complete audio.

Tonight's Sky for December 23: Moon Meets the Bull

Tonight, the Moon will be in a very unique place: right on the head of a cosmic bull. Tonight, the Moon will move directly into the Zodiac constellation of Taurus the bull, more specifically, into its head.

To see the sight, go out and look East. The Moon, of course, will be impossible to miss. Moon found, look for a sideways 'V' of stars (set off by bright orange Aldebaran), the Hyades star cluster, which represent the base of the bull's head. Extending the lines of the 'V' out, you will run into a pair of stars of roughly 2nd magnitude (though on opposite ends of the scale) that signal the end of the horns.


Cosmic picture realized, there's the Moon, smack in the middle. 

Tonight's Sky for December 22: The Winter Solstice


Today marks the Winter Solstice, the shortest day of the year for us living in the Northern Hemisphere and the official start of the summer season.

So, why do we have seasons, anyway?

It's all about Earth's tilt. If the Earth were spinning on its axis with no tilt at all, everyone would be treated to days of identical length every day of the year, with latitudes nearer the equator having longer days than those nearer the poles. However, with the tilt, the angle of the Earth relative to the Sun changes as or planet moves about its orbit. On the Winter Solstice the Northern Hemisphere is tilted up and away from the Sun. On the Summer Solstice, the Northern Hemisphere will be tilted down toward the Sun. On the equinoxes, the tilt is half way between the solstices. To see this effect, go out and observe the path the Sun takes through the sky for the course of day of a year.


Monday, December 21, 2015

Tonight's Sky for December 21: Ursid Meteors Peak

Tonight will mark the peak of the Ursid Meteor shower for 2015, thus marking the climax for the 2-week event. Every December, Earth passes through the stretch of space junk shed by Comet NAME, reaching the deepest concentration of debris tonight. According to some estimates, under ideal conditions (dark country skies), one can expect to see 10-15 meteors per hour. The reason the meteors are called Ursids is because the meteors seem to radiate from the constellation Ursa Major (the Great Bear), which contains the famous Big Dipper. The best time to view the shower is in the predawn, as Ursa Major is at its highest then.

Don't want to stay up that late? Don't worry, Ursa Major is circumpolar and is up all night. However, unless one lives out in the country, the early night hours will probably involve Ursa Majr being low in a light dome. To improve odds of seeing meteors, travel out of the city and to the country if you can. In the suburbs, just going from the front to back yard can make a dramatic difference as this will eliminate glare from those pesky street/house lights to a large extent.

Unfortunately, this year's Ursid peak coincides with the Full Moon. The good news: even the Moon won't be able to drown-out the brightest meteors with all its light.

Sunday, December 20, 2015

Tonight's Sky for December 20: Moon at Perigee

Tonight, the Moon is about as big as it will ever get thanks to the fact that the Moon is at perigee, a point in its orbit that is closest to Earth.


What many people may not realize is the fact that the Moon (and all other celestial bodies) do not orbit their parent bodies in circles, but ellipses, which are slightly elongated circles. Result: any given day of an orbital period, any orbiting body will be at a slightly different distance from its parent body. As for the Moon, this variance in orbit amounts to about 20,000 miles.

As for tonight, the Moon will be about as close to Earth as it is going to get. When it comes to practical implications, the difference will be hard to notice with the naked eye to all but an experienced observer but, in a telescope, the difference will be obvious

Friday, December 18, 2015

Tonight's Sky for December 18: First Quarter Moon


Today, the Moon, second brightest object in the sky, has reached the First Quarter phase, which means that it is exactly 90 degrees around its orbit of Earth and is one quarter finished with its current orbit..

As for lunar mechanics, the Moon is always half lit. The reason we don't always see it as such is thanks to orientation in relation to us. Right now, with the Moon at a 90 degree angle relative to the Earth-Sun line, we only see half of the lit side.

After today, we will see more of the Moon each night as its lit side turns more toward from us and heads toward Full in a week. 

Wednesday, December 16, 2015

Tonight's Sky for December 17: First Powered Flight (1903)

It was on this date in 1903 that the Wright Brothers made the first powered flight in human history. While earlier flights had been made with hot air balloons, the first heavier than air flight was a milestone for the simple reason that many people thought that it could never be done in the first place. While Orville Wright only got the Flyer a few feet off the ground for 12 seconds and traveled only about 120 feet, it was the root of all flight to follow, which would culminate in Apollo 11's Moon landing in 1969.

Tonight's Sky for December 16: E.E. Barnard Born (1857)

It was on this date in 1857 that the American astronomer Edward Emerson Barnard was born in Nashville, Tennessee.

Barnard gained fame as an amateur astronomer. As a hobbyist, Barnard discovered 5 comets after Hulbert Harrington Warner offered a prize of $200 per comet discovery. With this money, Barnard built a house for himself and his wife. This feat propelling him to fame, a group of Nashville amateurs pooled enough money to get Barnard into Vanderbilt University. Barnard never graduated but received the only honorary degree Vanderbilt ever awarded.

From there, Barnard moved onto working at observatories, where he discovered Iapetus and Amalthea, the fifth Moon of Jupiter and the last to be discovered visually. Working at the Yerkes Observatory, Barnard used the great 40-inch refractor and became a pioneer astrophotographer. Additionally, he discovered Barnard's Star, the second closest to Earth.

Tuesday, December 15, 2015

Tonight's Sky for December 15: Venera 7 Lands on Venus (1970)

It was on this date in 1970 that the Russian-built Venera 7 became the first spacecraft to both land on and transmit data from another planet. The data transmitted was minimal, a temperature reading of 887 degrees Fahrenheit, but it was the first data ever transmitted back to Earth from another planet. Later investigation came to the conclusion that the craft had probably bounced on landing and came to rest on its side, thus preventing the transmission of any further data thanks to the fact t hat the antenna was pointed down to the ground. 

Tonight's Sky for December 14: Geminids Peak

Tonight will mark the peak of the Geminid Meteor shower for 2015, thus marking the climax for the 2-week event. Every December, Earth passes through the stretch of space junk shed by the mysterious 3200 Phaeton (thought to be a spent comet now resembling an asteroid because all of its ice has melted), reaching the deepest concentration of debris tonight. According to some estimates, under ideal conditions (dark country skies), one can expect to see 100 meteors per hour. The reason the meteors are called Geminids is because the meteors seem to radiate from the constellation Gemini. The best time to view the shower is in the predawn, as Gemini is at its highest then.

Don't want to stay up that late? Don't worry, Gemini is clears the horizon around the time the sky gets truly dark, making this an all-night event. However, unless one lives out in the country, the early night hours will probably involve Gemini being low in a light dome. To improve odds of seeing meteors, travel out of the city and to the country if you can. In the suburbs, just going from the front to back yard can make a dramatic difference as this will eliminate glare from those pesky street/house lights to a large extent.

Fortunately, this year's shower coincides with the waxing crescent Moon, which means that nature's night light will be a non-issue. 

Sunday, December 13, 2015

Tonight's Sky for December 13: Thin Crescent

Didn't see last night's 12-hour Moon? Well, tonight's 36-hour Moon is no challenge to spot but still very appealing for people who like to observe thin crescents.

Saturday, December 12, 2015

Tonight's Sky for December 12: The Youngest of Moons

How thin of a Moon have you seen? How about one that's just barely over 12 hours old and only 0.5% illuminated? Well, if you have never seen a Moon this thin, this is your chance to do so as such a Moon will be making an appearance in this evening's sky just after sunset. 

To see the Moon, you'll need a good Western horizon. How good? One with less than 3 degrees of obstruction. To simulate this, hold your little finger vertically at arm's length to simulate 1 degrees. Hint: if you can't think of a good location off-hand, scout out one during the day. Location found, head there at sunset and start looking, preferably with optical aid, and start scanning the sky. The Moon may not be visible at first, often seeming to suddenly pop into visibility as if it were flipped on like a light.

Believe me, when this happens, it's an exhilarating experience but note: seeing a 12-hour Moon is a very, very (can't emphasize the 'very' enough) tough proposition as it is near the world record for the youngest Moon sighting. Hint: if you have a go-to scope, this would be a great time to utilize it! 

Friday, December 11, 2015

Tonight's Sky for December 11: New Moon


Today, the Moon, second brightest object in the sky, has reached the New Moon phase, which means that it is directly between the Sun and Earth, and thus invisible for us Earthlings as of now.

As for lunar mechanics, the Moon is always half lit. The reason we don't always see it as such is thanks to orientation in relation to us. Right now, with the Moon directly between the Earth and Sun, we can't see any of its lit side. 

Wednesday, December 9, 2015

Tonight's Sky for December 8: Astraea Discovered (1845)

It was on this date in 1845 that H.L. Hencke discovered Astraea, the 5th known asteroid. The first asteroid, Ceres (now classified as a dwarf planet), was discovered in 1801. In the intervening years, 3 more discoveries followed: Pallas, Juno, and Vesta. Interestingly, at the time of its discovery, Astraea was classified as a planet, along with the other 4 objects now known to reside in the asteroid belt. However, with the advances in lens making that made the construction of far larger telescopes possible, the discovery of objects in the asteroid belt accelerated to the point where it became too cumbersome to classify these objects as planets. Result: by the end of the 1850s, these objects were known as asteroids (from the Greek for 'star-like') and, as more were discovered, the term 'asteroid belt' eventually came into use.

Monday, December 7, 2015

Tonight's Sky for December 7: Moon Meets Venus


Want to see the planet Venus but have no idea where to look? Well, no problem because, at least for this morning, the Moon will be parked right next to Venus, second planet from the Sun and third brightest object in the sky (after the Sun and Moon).

Sunday, December 6, 2015

Tonight's Sky for December 6: Mars Rises 5 Hours Before the Sun With Moon

Want to see the planet Mars but have no idea where to look? Well, no problem because, at least for this morning, the Moon will be parked right next to Mars, fourth planet from the Sun. Try and see if you can notice its reddish tinge when compared to close-by Venus and Jupiter.


Additionally, Mars is now rising 5 hours before the Sun.

Saturday, December 5, 2015

Tonight's Sky for December 5: The Earliest Sunsets, Moon at Apogee

While the shortest day of the year, the Winter Solstice, is about two weeks away, the earliest sunsets of the year will occur this week for us here on Earth, regardless of where you live, despite the fact that sunset times vary depending on latitude.
Right now, the Sun is setting at its earliest time and will continue to set at the same time for the next few days before gradually creeping later into the evening.
So, with the Sun down so early (and resulting in the longest nights of the year), why not head out and view the stars? After all, the December sky has a lot to offer. After all, at what point of the year can you see a year's worth of stars in a given night? Don't believe me? Head out just after dark tonight and look up for the Summer Triangle. Then, just before sunrise, go out again and look for a bright blue star in the Northeast just above the horizon. That's Vega, the same Summer Triangle Star you saw the previous night.

Additionally, the Moon is about as small as it will ever get thanks to the fact that the Moon is at apogee, a point in its orbit that is farthest from Earth.


What many people may not realize is the fact that the Moon (and all other celestial bodies) do not orbit their parent bodies in circles, but ellipses, which are slightly elongated circles. Result: any given day of an orbital period, any orbiting body will be at a slightly different distance from its parent body. As for the Moon, this variance in orbit amounts to about 20,000 miles.

As for tonight, the Moon will be about as far from Earth as it is going to get. When it comes to practical implications, the difference will be hard to notice with the naked eye to all but an experienced observer but, in a telescope, the difference will be obvious

Friday, December 4, 2015

Tonight's Sky for December 4: Moon Meets Jupiter

Want to see the planet Jupiter but have no idea where to look? Well, no problem because, at least for this morning, the Moon will be parked right next to Jupiter, fifth planet from the Sun and largest planet in the solar system.  

Thursday, December 3, 2015

Tonight's Sky for December 3: Third Quarter Moon


Today, the Moon, second brightest object in the sky, has reached the Third Quarter phase, which means that it is exactly 270 degrees around its orbit of Earth.

As for lunar mechanics, the Moon is always half lit. The reason we don't always see it as such is thanks to orientation in relation to us. Right now, with the Moon at a 90 degree angle relative to the Earth and Sun, we see the Moon as half lit and half dark, leading to the popular, erroneous phrase 'half Moon.'

After today, we will see less and less of the Moon as its lit side turns more away from us and heads toward new phase.

Wednesday, December 2, 2015

Tonight's Sky for December 2: Moon Meets Regulus

New to astronomy? Want to see Regulus, the alpha (brightest star) in Leo but don't know where to look? Well, it's your lucky night as the Moon will be right next to Regulus this morning. 

The moon is, of course, impossible to miss. As for Spica, it's that bright star right next to Luna. To see the show, go out early in the night just after the sky gets dark.

Tuesday, December 1, 2015

The December Sky

With new month of December upon us, people in the Northern Hemisphere will be treated to the longest nights of the year as the Winter Solstice arrives on the 22nd of this month. However, when it comes to changes in days' lengths, December is pretty much a story of steady 15 hour nights, give or take a few minutes at most. So, with all of this night, what's there to see?

Cool Constellations
By nightfall in December the fall constellations are all very well-placed for early (emphasis, early!) evening viewing. First up, we will have one last chance to see the summer constellations, provided you have a good West horizon. Hurry, though, they'll quickly disappear (at least in the West) for good by month's end. Moving onto more mainstream celestial landmarks for this time of year, the Great Square of Pegasus is high overhead and the Big Dipper is scraping the Northern horizon. Starting at the Great Square, look at the double string of stars coming of third base as they constitute Andromeda. High in the Northeast is ‘W’-shaped Cassiopeia, house-like Cepheus, and a twisted ‘V’ of stars, the mythological hero Perseus. Below Perseus is the bright Capella, alpha Auriga, and below his feet, the cloudy patch that is the Pleiades. In the early evening, the South, save bright Fomalhaut, is a dark void populated by the dim constellations of Capricorn, Aquarius, Pisces, and Cetus. If you stay up a little later as in a couple of hours after dark (which is no longer a chore/something you later regret doing at this time of year), you'll see all the winter favorite like unmistakable Orion in the South, which also serves as a winter signpost to the stars. From Orion, follow a line from his belt down to blazing blue Sirius, alpha Canis Major. Following that line up will bring one to Aldebaran, alpha Taurus the bull. Imagining a line starting at bright blue Rigel (Orion's left foot) through red Betelgeuse (Orion's right shoulder) will bring you to Castor and Pollux, alpha and beta Gemini. Other winter favorites to look for include Canis Minor, Cancer, and even Leo if you wait into the night a little longer. Early birds? Well, getting up just before the Sun will bring a spring preview in the form of Virgo, Bootes, Corona, Hercules, Corvus, and even Vega just ahead of the rising Sun.

Planetary Perceptions
On the planet front, if you want to see any of our solar system neighbors, you had better be an early bird because 4 of the 5 naked eye planets make their appearances in the predawn morning sky. For starters, Jupiter and Mars both continue their climbs in the predawn Eastern sky while Venus continues dropping, which is what it began to do in October and then, noticeably in November. Also of note, the Moon will be making several near passes of these bodies in the early part of the month. As for Saturn, which disappeared into the dusk glow back in mid November, it re-emerges as a morning planet mid month and, by month's end, should be relatively easy to spot low in the predawn, Eastern sky. As for Mercury, it will become the sole evening planet when it pops out of the Sun's glare in the evening sky mid month as it heads towards greatest elongation (best visibility) around the start of the new year.


Tonight's Sky for December 1: Benjamin Wilson Born (1811)
It was on this date that Benjamin Wilson, namesake of Mt. Wilson, was born. Originally from Tennessee, Wilson traveled to California hoping to obtain passage to China but was unable to do so. Instead of traveling back home, Wilson settled in Southern California where he became a prominent politician and businessman. Wilson died in 1878 at age 66 and Mt. Wilson, Informally known as Wilson's Mountain because he owned the land on which it sat, thte name would eventually become official.

Monday, November 30, 2015

Tonight's Sky for December 30: Venus Rises 3 Hours Before the Sun


This morning, Venus, second planet from the Sun and third brightest object in the night sky, will be rising 3 hours before the Sun. Now, while not as early as the 4 hours before the Sun rise that was taking place last month, any morning planet rising 3 hours before the Sun mean t hat it will still be pretty high come the predawn hour.  

Sunday, November 29, 2015

Tonight's Sky for November 29: Jupiter Rises 6 Hours Before the Sun


Jupiter is getting more viewer-friendly by the day as it continues to climb a little higher in the sky every night as it heads towards its eventual opposition, which is not set for until March. As of tonight, the King of the planets is rising 6 hours before the Sun, meaning that it is getting high in the Southeast come dawn. 

Saturday, November 28, 2015

Tonight's Sky for November 28: Mariner 4 Launched (1964)


It was on this date in 1964 that NASA launched its Mariner 4 spacecraft, which was the first spacecraft to make a successful Mars flyby. Returning two dozen tantalizing pictures of Mars in 1965, Mariner 4 also shattered the long-held belief that Mars was a hospitable world the could be home to advanced life.

It may be hard to believe now but, in 1964, there was no proof that Mars couldn't be home to advanced civilizations. At the time, the polar ice caps looked decidedly Earth-like and the changing surface of the planet was interpreted by some as the growing and dying of seasonal vegetation. This, combined with the famous canals, conspired to paint a picture of a planet friendly to life that served as inspiration for hundreds of science fiction comics, books, and films despite the fact that advances in science since the time of Percival Lowell and HG Wells were, stroke by stroke, painting a picture of a cold, dry world.

Still, the only way to know anything for sure was to visit Mars for a close-up look.

Upon flyby in 1965, Mariner 4 revealed a cold, desolate, virtually airless world totally incapable of supporting advanced life as we know it. Still, 50 years later, while some still cling to the hope for microbial life, it's clear that there is no advanced life on Mars, forcing sci-fi writers of the present to set their works in other solar systems rather than this one.  

Friday, November 27, 2015

Tonight's Sky for November 27: Algol at Minimum at 9:04pm EST


This evening, Algol, located in Perseus, will be at minimum at 9:04pm Eastern Standard Time. No, the star does not turn off and on again like a light bulb, but it will gradually dim and then brighten again, going from magnitude +2.1 to +3.4 and back to +2.1 over the course of a couple of hours. Good companion stars with which to compare Algol are Gamma Andromeda (magnitude 2.1) to Algol's right and Mirfak (magnitude 1.8) above and left of Algol. Fortunately, it will be possible to see the event in entirety thanks to the timing. To see the show, go out as soon as it gets dark, then at around 9:04, then a few hours later. Try and spot the difference. 

The reason for this change in brightness? Algol is not a single star, but a two star system, as many stars are. However, what sets Algol apart is that, as seen from Earth, the dimmer companion eclipses the main, brighter star. The result: a dramatic change in brightness that earned the star its name ('Algol' is Arabic for 'the ghoul') and the nickname 'the winking demon star.' 

Wednesday, November 25, 2015

Tonight's Sky for November 25: Full Moon Meets the Clusters


Tonight, the
Moon will reach its full phase, which means that, as seen from Earth, it is directly opposite the Sun in the sky as seen from Earth and is at the half way point in its current orbit.

As for lunar mechanics, the Moon is always half lit. The reason we don't always see it as such is thanks to orientation in relation to us. Right now, when the Moon is opposite the Sun and on the far side of Earth, we can see all of its lit side, which is why it appears to be “full.” In the coming nights, we will start to see less of the Moon as its lit side starts to turn away from us as seen from Earth and heads toward Third Quarter.


On top of that, the Moon forms a triangle with the Pleiades and Hyades star clusters, too. 

Tuesday, November 24, 2015

Tonight's Sky for November 24: Be Alert for Aurora

Tonight, NOAA is estimating a 40% chance of geomagnetic storms at high latitudes, which means that people living in the Northern U.S. and similar latitudes should keep an eye on the sky for aurora tonight. 

Monday, November 23, 2015

Tonight's Sky for November 23: Can You See Comet Catalina?


It's finally here! After spending its time giving Southern Hemisphere observers a show, Comet Catalina went around the Sun and has now reappeared in the Northern sky. As of now, the comet, estimated to be around +7 magnitude, is a challenge as it is very close t the Sun and the window to catch it between its rising and being out-shone by the rising Sun is very small. However, that will change as the days progress. In fact, come New Years Day, the comet will be within ½ degree of bright Arcturus, alpha Bootes, which will be very high in the predawn sky. So yes, you may not be able to catch it now but, in the coming weeks, keep your eyes out for Comet Catalina, which is expected to brighten to +5 magnitude by Christmas.

Sunday, November 22, 2015

Tonight's Sky for November 22: Remembering NASAs Greatest Champion


It was on this date in 1963 that NASA lost its greatest champion when President John F. Kennedy was assassinated in Dallas, Texas. When boldly declaring that America would go to the Moon by the end of the decade, President Kennedy kicked the Space Race into high gear and made it a matter of national pride to get to the Moon. Result: NASA was given pretty much anything it needed to make the president's dream a reality.


Today, it is a common misconception that NASA is a huge part of the federal budget, with some respondents to surveys stating that they believe that NASA could account for as much as 20% of the federal budget. In fact, nothing could be further from the truth. As of 2015, NASA's budgetary allowance was only about 0.5% the federal budget. In the 60s? The story was very different. In the lead-up to Apollo, NASA got a lot more money, peaking at 4.4% of the total federal budget in 1966.

Today, such a thing would be unheard of but today, the idea of an entire nation, regardless of political affiliation, rallying behind the space program, is just as unheard of, too. 

Saturday, November 21, 2015

Tonight's Sky for November 21: Alpha Monocerotids Peak


Tonight will mark the peak of the Alpha Monocerotid Meteor shower for 2015, thus marking the climax for the 2-week event. Every November, Earth passes through the stretch of space junk shed by a comet of still unknown origin, reaching the deepest concentration of debris tonight. Of all meteor showers, this one is among the weakest, only often producing a few meteors per hour but, curiously, there is a tendency by the Alpha Monocerotids to have outbursts on years ending in 5. Some of these outbursts, while often less than an hour in duration, result in va rate of hundreds of meteors per hour.. The reason the meteors are called Alpha Monocerotids is because the meteors seem to radiate from the constellation Monoceros, specifically its alpha (brightest) star. The best time to view is anytime since Monoceros is up all night.

To improve odds of seeing meteors, travel out of the city and to the country if you can. In the suburbs, just going from the front to back yard can make a dramatic difference as this will eliminate glare from those pesky street/house lights to a large extent.

Unfortunately, this year's peak coincides with the Full Moon. The good news: even the Moon won't be able to drown-out the brightest meteors with all its light..

Friday, November 20, 2015

Tonight's Sky for November 20: Mars at Aphelion

Today, Mars is as far as it will ever get from the Sun thanks to the fact that it is at aphelion, a point in its orbit that is farthest from Sun.

What many people may not realize is the fact that Mars (and all other celestial bodies) do not orbit their parent bodies in circles, but ellipses, which are slightly elongated circles. Result: any given day of an orbital period, any orbiting body will be at a slightly different distance from its parent body. As for Mars, this variance in orbital distance to the Sun amounts to about 26 million miles, a difference of roughly 13 million miles from its average distance from the Sun, 143 million miles.


Additionally, Mars is as slow as it will get today, too. Why is this? As a planet locked in an orbit gets farther from the Sun, the Sun's gravitational force on the planet lessens and the planet will slow down. Then, as the planet round the aphelion point and begins to move closer to the Sun, its speed will increase as the distance to the Sun decreases, culminating at maximum speed at, you guessed it, perihelion. This fact was first discovered in the early 1600s by Johannes Kepler and serves as his 2nd law of planetary motion, the law of equal areas.  

Tonight's Sky for November 19: First Quarter Moon

Today, the Moon, second brightest object in the sky, has reached the First Quarter phase, which means that it is exactly 90 degrees around its orbit of Earth and is one quarter finished with its current orbit..

As for lunar mechanics, the Moon is always half lit. The reason we don't always see it as such is thanks to orientation in relation to us. Right now, with the Moon at a 90 degree angle relative to the Earth-Sun line, we only see half of the lit side.

After today, we will see more of the Moon each night as its lit side turns more toward from us and heads toward Full in a week.

Thursday, November 19, 2015

Tonight's Sky for November 18: Venus Rises 4 Hours Before the Sun


Venus may not be as high as it once was in the predawn sky, but it's still very well-placed, as evidenced by the fact that it is still rising 4 hours before the Sun. 

Tuesday, November 17, 2015

Tonight's Sky for November 17: Leonid Meteors Peak

Tonight will mark the peak of the Leonid Meteor shower for 2015, thus marking the climax for the 2-week event. Every October, Earth passes through the stretch of space junk shed by Comet Tempel-Tuttle, reaching the deepest concentration of debris tonight. According to some estimates, under ideal conditions (dark country skies), one can expect to see 20-30 meteors per hour. The reason the meteors are called Leonids is because the meteors seem to radiate from the constellation Leo. The best time to view the shower is in the predawn hours, as Leo is at its highest then.

To improve odds of seeing meteors, travel out of the city and to the country if you can. In the suburbs, just going from the front to back yard can make a dramatic difference as this will eliminate glare from those pesky street/house lights to a large extent.

Fortunately, this year's Leonid peak coincides with the First Quarter Moon, which means that nature's night light will be a non-issue as it will have long since set by the time the predawn hours arrive.

Monday, November 16, 2015

Tonight's Sky for November 16: Last Chance to Catch Saturn


Anyone wanting to catch the planet Saturn before it disappears into the Sun's glare had better do so now as the ringed wonder is setting only an hour after the Sun. In practical terms, that means that a pair of binoculars is in order and that one had better go out about 15 minutes after sunset and look very low in the West-Southwest. With a good horizon, you should be able to find Saturn. Don't see it right away? No problem, planets are often hard to spot at dusk and when they do finally pop out of the twilight, it is almost as though a light was flipped on as you'll have probably scanned that area of sky several times beforehand. 

Sunday, November 15, 2015

Tonight's Sky for November 15: Perseus at Zenith at Midnight


Tonight at midnight, mythological Hero Perseus will be at zenith (straight up). This constellation is an interesting one for several reasons, so let's examine them. First up, its alpha (brightest) star is Mirfak and it, along with Fomalhaut, are the only stars brighter than 2nd magnitude in the entire fall sky. Second, Perseus' beta (2nd brightest) star is Algol, and it's an eclipsing binary star. What does that mean? When the dimmer companion moves in front of the brighter main star, Algol will show a noticeable drop in brightness over the course of several hours. This so creeped out the ancients that the very name Algol means “the ghoul” in Arabic. The star is also known as the Winking Demon Star. Third, above Perseus and about half way to W-shaped Cassiopeia ;lies the Double Cluster, a dazzlingly beautiful pair of open clusters populated by blue stars. High power binoculars or a low power eyepiece in a telescope work best here.

Saturday, November 14, 2015

Tonight's Sky for November 14: Fomalhaut Due South at Dark


You may have noticed that the fall sky does not have a lot of bright stars when compared to summer. In fact, the fall sky does not have a single star in the 0 or brighter magnitude range. The star that does come closest at magnitude +1.1 is Fomalhaut (pronounced “foam a lot”), and it is just about due South when the sky gets truly dark, which is about an hour and a half after sunset. Fomalhaut is the alpha (brightest) star of Pisces Australis, the Southern Fish. Adding to Fomalhaut's prominence is the fact that, at mid-Northern latitudes, there are no bright stars in the Southern sky with the stars of the Great Square (2nd magnitude) being the most Southerly stars of any real brightness. For that reason, many people think Fomalhaut s brighter than it actually is. 

Friday, November 13, 2015

Tonight's Sky for November 13: Leonid Storm (1833)


In November, 1833, meteor showers were recognized, though their exact origin had yet to be  determined at that time. Through centuries of observation, scientists and amateur sky watchers noticed that showers always seemed to take place on the same dates over the course of decades. In time, the showers became known by the name of the constellation from which they seemed to radiate from. So, when meteors started to appear from the constellation Leo in the middle of November, no one was surprised.

Then came the morning of November 13.

On the night of the 12th, many sky watchers noticed that there seemed to be an unusually high number of meteors in the sky heading into the morning of the 13th. Suddenly, as if someone turned on a switch, the sky filled with meteors to the tune of, according to the high estimates, over 200,000 per hour! That translates to over 3,000 per minute or, even more mind boggling, 50 meteors per second. All across North America, people were woken by their bedrooms suddenly becoming filled with light (the electric light was over 40 years in the future) thanks to the light of all the meteors. Now, the kicker: this lasted for 4 hours until the Sun started to rise.

Needless to say, reactions to the shower, which just about turned night into day, were quite varied. Naturally, those well-versed in the sciences were excited as no meteor shower of anywhere near this magnitude had ever been seen before. On the other hand, for a lot of the less well educated, panic ensued as many thought that Judgment Day was at hand, that the stars were falling, and that the earth would soon be destroyed.

As night gave way to morning, some of the meteors were so bright as to be seen by day, a true rarity for meteors. However, while the shower lasted only about 4 hours at its outburst phase, its implications were much more long-lasting as this event, more so than any other to that time, did much to drive knowledge and make the study of meteors and meteor showers a true scientific study.

Thursday, November 12, 2015

Tonight's Sky for November 12: Young Moon Meets Saturn


How thin of a Moon have you seen? How about one that's just barely over 2 days old and only 5% illuminated? Well, if you have never seen a Moon this thin, this is your chance to do so as such a Moon will be making an appearance in this evening's sky just after sunset.

To see the Moon, you'll need a good Western horizon. How good? One with less than 10 degrees of obstruction. To simulate this, hold your fist vertically at arm's length to simulate 10 degrees. Hint: if you can't think of a good location off-hand, scout out one during the day. Location found, head there at sunset and start looking, preferably with optical aid, and start scanning the sky. The Moon may not be visible at first, often seeming to suddenly pop into visibility as if it were flipped on like a light.

Believe me, when this happens, it's an exhilarating experience.

To make things easier, Saturn is nearby, too.

Wednesday, November 11, 2015

Tonight's Sky for November 11: New Moon


Today, the Moon, second brightest object in the sky, has reached the New Moon phase, which means that it is directly between the Sun and Earth, and thus invisible for us Earthlings as of now.

As for lunar mechanics, the Moon is always half lit. The reason we don't always see it as such is thanks to orientation in relation to us. Right now, with the Moon directly between the Earth and Sun, we can't see any of its lit side.

After today, we will see more of the Moon each night as its lit side turns more toward from us and heads toward first quarter.

Tuesday, November 10, 2015

Tonight's Sky for November 10: Old Moon

How thin of a Moon have you seen? How about one that's just barely a day before New and only 2% illuminated? Well, if you have never seen a Moon this thin, tonight's your chance to do so as such a Moon will be making an appearance in this morning's sky just before sunrise. 

To see the Moon, you'll need a good Eastern horizon. How good? One with less than 3 degrees of obstruction. To simulate this, hold two fingers vertically at arm's length to simulate 3 degrees. Hint: if you can't think of a good location off-hand, scout out one during the day. Location found, arrive there about 15 minutes before sunrise and start looking, preferably with optical aid. The bad news: you'll have to hurry because, as soon as the Sun clears the horizon, you can forget about seeing the Moon. 

Monday, November 9, 2015

Tonight's Sky for November 9: Carl Sagan Born (1934)


It was on this date in 1934 that Carl Sagan, perhaps the most famous astronomer of the 20th century, was born. Sagan's 'personal voyage' into discovery began at a young age with a question: what are the stars? It was this quest to find the answer to this question that set the course of Sagan's life and propelled him into a 30+ year career as a scientist that is, ironically, often overlooked thanks to his iconic Cosmos TV series and accompanying book. Cosmos, unlike Sagan's academic work, Cosmos presented no new ideas nor validated any old theories, but rather made the science of astronomy understandable to the masses. It was for this reason, his ability to communicate complex ideas in a way that anyone could understand, that Sagan became to be seen as a star educator rather than a scientist, per se. Sagan would continue to be viewed in this light until his death in December, 1996. To date, his shoes have gone unfilled to millions the world over.  

Sunday, November 8, 2015

Tonight's Sky for November 8: Be Alert for Aurora


Yesterday, a coronal mass ejection (CME) impacted Earth's atmosphere, triggering a display of aurora, also known as the Northern Lights. Tonight, NOAA is reporting that there is a 50-60% chance for continued geomagnetic storms (and thus aurora) tonight for those of us living at high latitudes, so keep an eye on the sky!

Saturday, November 7, 2015

Tonight's Sky for November 7: Moon Meets Venus, Mars


It was Jupiter yesterday and today, it's Venus and Mars meeting with the Moon, with Luna parked only slightly more than a degree from Venus. Mars, which should appear reddish, is also close by as is beta Virgo.

Friday, November 6, 2015

Tonight's Sky for November 5: 5-Body Cosmic Lineup


This morning, one will be treated to a very unique meet-up of celestial bodies along the Ecliptic Plane that consists of 3 planets, a star, and the Moon.

So, what's there to see?

First of all, to see the show, go out in t he predawn hours and look East. That done, find the Moon, which is the second highest object in the line. Moon found, look above to find a bright blue star, which is Regulus, alpha Leo. Dropping below the Moon, the three bright 'stars' are actually planets, more specifically Jupiter, Mars, and Venus in that descending order.

Wednesday, November 4, 2015

Tonight's Sky for November 4: Venera 14 Launched (1981)

It was on this date in 1981 that the Soviet Union launched its Venera 14 spacecraft. Like its twin, Venera 13, Venera 14 was equipped with color cameras and a spring-loaded arm to measure how compressible the ground was. However, the arm experiment failed thanks to the fact that the arm landed right on a lens cap that popped off (by design) from one of the cameras, meaning that the arm measured the compressibility of the lens cap rather than the soil.

Tuesday, November 3, 2015

Tonight's Sky for November 3: Venus and Mars Within Half a Degree, Third Quarter Moon

They've been converging for the past week or so and, tonight, Venus, second planet from the Sun and second brightest object in the night sky, will be within half an angular degree of Mars, fourth planet from the Sun. To see the pair, simply go out in the predawn hours and look East. Venus? It's the brightest thing in the sky. Venus found, that dim, reddish 'star' right next to it is, in fact, Mars. 

If that weren't enough, the Moon is also at Third Quarter phase today, too.

Monday, November 2, 2015

Tonight's Sky for November 2: Summer in November

The calendar may say November (and thus fall), but don't tell that to the stars as the summer sky is still well-placed come the arrival of dark skies thanks t o falling back an hour. Needless to say, it won't be hanging around for much longer, so make it a point to get out and look up soon!

Sunday, November 1, 2015

The November Sky

With new month of November upon us, the nights are coming increasingly early on account of both the Sun's motion and the big event of the month: the return to Standard Time, which occurs on the morning of the 1st. Also by November, the fall sky has firmly taken its place high overhead by nightfall (not to be confused with sunset), which will be happening at its earliest time of the year late this month thanks to some odd celestial.

Cool Constellations
By nightfall in November the fall constellations are all very well-placed for early (emphasis, early!) evening viewing. First up, with the return to Standard Time, we will have one last chance to see the summer constellations, provided you have a good South and West horizon. Hurry, though, they'll quickly disappear for good for the year, though. Moving onto more mainstream for the time of year sights, the Great Square of Pegasus is high overhead, the Big Dipper is scraping the Northern horizon, and the Summer Triangle is starting to dive in the West. Starting at the Great Square, look at the double string of stars coming of third base as they constitute Andromeda. High in the Northeast is ‘W’-shaped Cassiopeia, house-like Cepheus, and a twisted ‘V’ of stars, the mythological hero Perseus. Below Perseus is the bright Capella, alpha Auriga, and below his feet, the cloudy patch that is the Pleiades. In the South, save bright Fomalhaut, all the constellations, Capricorn, Aquarius, Pisces, and Cetus, are very dim. If you stay up later into the middle of the night, you'll see bright Orion, Gemini, and Canis Major. Early birds? Leo and Virgo will be headlining the spring (it's only 4 ½ months away!) constellations.

Planetary Perceptions
On the planet front, if you want to see any of our solar system neighbors, you had better be an early bird because 4 of the 5 naked eye planets make their appearances in the predawn morning sky. For starters, Jupiter and Mars both continue their climbs in the predawn Eastern sky while Venus continues dropping, which is what it began to do in October. At the start of the month, Mercury will still be hanging around low in the Eastern predawn sky but not for long as it will quickly drop into into the Sun's glare and out of sight for the remainder of November. Lastly, there's Saturn, the sole evening planet, which presents a last chance to view it as it will disappear into the Sun's glare by mid month.


Last but not least, mark your calendars for the morning of the 26th, which is the day the Moon will occult (eclipse) Aldebaran around 5:30am EST. While lunar occultations of stars are not overly rare, an occultation of such a bright star is a bit of a rarity. To see the show, go out about 5am and train your telescope on the Moon. To get exact time Aldebaran will suddenly blink off (there being no atmosphere on the moon, there will be no dimming, only an abrupt disappearance) go to this website and plug in your latitude and longitude. As the time approaches, tare into the eyepiece and wait for the eye of Taurus to abruptly vanish. Another idea: hook up a video recording device to the telescope and record the event as it happens! Yes, it comes at anything but a convenient hour for most people but this is an event worth getting up early for! 



Tonight's Sky for November 1: Cross-Quarter Day, “Standard” Time Returns
Today marks 2 interesting dates for astronomers in that November 1 is a cross-quarter day, which is a fancy way of saying that it represents the mid-point of a season. For the ancient farmers, timekeeping was a matter of life and death and cross-quarter days provided a more precise way of dividing the year into parts (8) than seasons (4). For that reason, a cross-quarter day marking the mid point of a season was very important to our distant ancestors.


Additionally, “Standard” (it only lasts 4 months and is hardly “standard” if you ask me) Time returned at 2am this morning. Hopefully you set back your clocks before bed last night!

Saturday, October 31, 2015

Tonight's Sky for October 31: Galileo Half Off the Hook (1992)


It was on this date in 1992 that the Vatican admitted that it had made “errors” in its handling of Galileo and his teachings over 3 ½ centuries earlier when it brought the famed astronomer before the Inquisition on charges of heresy for teaching that the Earth is not the center of the solar system. However, while admitting “errors,” the Vatican would not admit that it had been wrong. Still, for many in the scientific community, this was a move in the right direction a long, long time in the making.

Don't Forget:
Set your clocks back an hour tonight before bed as Standard Time will return at 2am tomorrow (Sunday). So, knowing you'll be gaining an hour, please take the time to check out some cool time change trivia because, after all, doing so will only take a few seconds!

*Many ancient civilizations divided their days into 24 hours just like us, but adjusted the 'hours’ lengths so that there would always be 12 hours of day and 12 of night (this had to make setting up a date really suck). 

*While he did not propose DST, Benjamin Franklin, while serving as envoy to France, anonymously published a letter, a rather tongue in cheek one at that, suggesting people rise early (and thus go to bed earlier) to economize on candles and make use of natural sunlight. So no, don't blame Ben Franklin for our having to change the clocks (and you being an hour late for church this morning if you forgot to do so!)

*Around the year 1900, two men would bring the idea of an actual time change (rather than the wake up/go to bed time change proposed by Franklin) to the public forefront. In England, prominent builder/outdoorsman William Willet, like Franklin, hated the idea that people were sleeping half their mornings away and, on a personal note, hated having to cut his rounds of golf short due to early nightfall. At the same time, New Zealand entomologist George Vernon Hudson proposed the same thing. Hudson's personal stake: extra daylight would allow more time for specimen collection. The idea failed to gain traction in either hemisphere.


* The catalyst for starting DST: WWI. The idea: push night an hour later so there would be less coal usage and the money saved on coal could be spent on the War. In summer 1916, the Central Powers (Germany, Austria-Hungary, and their allies) agreed to set the clocks ahead for an hour as a means for achieving this goal. The other belligerents quickly followed suit. The United States, which entered the war in 1917, adopted a time shift in 1918. After the War, DST was dropped until, you guessed it, WWII, after which it largely remained in use around the world.

*While we shift by an hour today, twenty and thirty minute shifts, and also two hour shifts, have been used in the past and are currently used in different places over the world.

* The Uniform Time Act of 1966 standardized DST start/stop dates for the United States even though it doesn't require states to observe DST (Arizona and Hawaii don't).

*Even now, start/end dates aren’t standard around the world

*Switch dates are reversed in the Southern Hemisphere

*In some areas, voters have rejected use of DST altogether while in other areas, there are pushes to eliminate Standard Time and have DST all year long (thus making DST the new Standard Time).

*'Standard' Time only lasts 4 months of the year thanks to DST being extended by 3 weeks in spring and 1 week in fall back in 2007 (hardly standard if you ask, me, how about calling it Daylight Losing Time?)

Friday, October 30, 2015

Tonight's Sky for October 30: Venera 13 Launched (1981)


It was on this date in 1981 that the Soviet Union launched its Venera 13 Venus probe. Upon landing on March 1, 1982, Venera 13 would transmit the first color pictures of Venus back to Earth, revealing a world bathed in filtered, orange light.

Thursday, October 29, 2015

Tonight's Sky for October 29: John Glenn Returns to Space (1998)



It was on this date in 1998 that John Glenn, the first American to orbit the Earth (1962), returned to space at age 77 aboard the space shuttle Discovery as part of the STS-95 mission. Because of the high publicity surrounding Glenn's participation in the mission, this was the first shuttle launch televised coast-to-coast. Additionally, the mission saw the first Spanish-born astronaut in space as Pedro Duque also took part on the mission. In addition to solar and the standard life science experiments, special focus was put on Glenn and the study of the aging process, both on Earth and in orbit. In all, the mission lasted just under 9 days. As for Glenn, he not only made it through the mission without any medical issues, but he also has stated that he really enjoyed his return to orbit, too.   

Wednesday, October 28, 2015

Tonight's Sky for October 28: NASA Launches Aries I-X (2009)

It was on this date in 2009 that NASA launched its Aries I-X prototype rocket, which was very similar to the Aries I, which was to be used in the Constellation Program, which was launched by then-president George W. Bush and designed to return Americans to the Moon by the late 2010s. Of course, as anyone familiar with NASA known, incoming president Obama canceled Constellation and this launch would go down as the only launch for anything related to Constellation. 

Tuesday, October 27, 2015

Tonight's Sky for October 27: Full Moon

Tonight, the Moon will reach its full phase, which means that, as seen from Earth, it is directly opposite the Sun in the sky as seen from Earth and is at the half way point in its current orbit.


As for lunar mechanics, the Moon is always half lit. The reason we don't always see it as such is thanks to orientation in relation to us. Right now, when the Moon is opposite the Sun and on the far side of Earth, we can see all of its lit side, which is why it appears to be “full.” In the coming nights, we will start to see less of the Moon as its lit side starts to turn away from us as seen from Earth and heads toward Third Quarter. 

Sunday, October 25, 2015

Tonight's Sky for October 26: Jupiter Meets Venus


In a second act to the October 8-10 series of conjunctions, we now have a close meet-up between the two brightest planets in the night sky: Venus and Jupiter, which will pass about 1 angular degree from each other. Yes, while not overly close, a conjunction of the two brightest planets will certainly be worth a look. To see the show, simply go out before sunrise and look East. 

Saturday, October 24, 2015

Tonight's Sky for October 24: The Awesome Great Andromeda Galaxy at Zenith at Midnight

Tonight, the Great Galaxy (there are many) in Andromeda will be at zenith (straight up) at midnight. This is an interesting sight for three cool facts that many people do not even know about..

First up: being a lover of trivia, the Great Galaxy is the most distant (2.7 million light years) object capable of being seen under all but the darkest skies (eagle-eyed observers may be able to see more distant galaxies under the darkest of skies, of which none exist East of the Mississippi). To put that in perspective, when the photons of light that you see radiating from Andromeda tonight left the galaxy, there were no humans, although our distant ancestors were starting their long journey from ape to human. Not only do astronomers see across space, they see through time. Another big thought: if the galaxy were to fall into the monster of all black holes (no black hole is that big) tonight, we wouldn't know about it for another 2.7 million years. 


The night sky in a couple billion years.

Second: we are looking at a crash of cosmic proportions in progress. Our own Milky Way Galaxy and Andromeda are gravitationally bound together, being by far the largest members in our galactic neighborhood, known as the Local Group of galaxies. Unfortunately, these two titans are on a collision course. In about 4 billion years, the Milky Way and Andromeda will 'crash' into each other at a combined speed of around 250,000 mph (or about 70 miles per second). Why the quotes? While the galaxies will run into each other, the chance of two stars actually hitting each other are virtually non-existent thanks to the immense distances that separate the stars. What will happen according to current models is this: the collective gravitational interaction of the two galaxies moving through each other will fling stars in all directions and the stars not flung out into space will eventually slow down and form a combined galaxy.

Third: as another fun point of trivia, the Great Andromeda Galaxy was the subject of one of the first deep-sky astrophotos. Photography as we know it was invented in 1827 and shortly thereafter astronomers started pointing camera-equipped telescopes at the Moon, with impressive results. Below is the first known photograph of the Moon, taken by JW Draper in March, 1840 with a daguerreotype camera. 

The 1st known picture of the Moon.

However, while quick lunar snaps were easy to master, long exposures required to gather enough photons to produce an image of a dim deep sky object required both advances in camera (more sensitive media) and observatory (more precise tracking) technology. Result: the first photos of a deep sky object (M42 and the Pleiades) was not taken until 1886 by Issac Roberts, who would go on to photograph Andromeda in the following year. That photo is below.


Friday, October 23, 2015

Tonight's Sky for October 23: Mole Day

Today is Mole Day. Why? Because today is 10-23, which is the latter half of the equation of 6.02x1023, which is the latter half of the equation representing Avogadro's Number, which in itself represent the number of atoms in 1 Mole (Mol) of any given substance Why the fascination with the Mole for chemists? One mole of any substance contains Avogadro's Number of molecules or atoms of that substance, making the Mole a handy unit of measure to uses when doing chemical calculations. This fact was discovered by Amadeo Avogadro (1776-1858). While started by chemists, Mole Day is now commonly celebrated by science enthusiasts in general.

Mole Day Joke:
Papa mole sticks his head out of his hole. What does he smell? Nothing.
Mama mole squeezes out of the hole next to Papa. What does she smell? Nothing.
Junior mole tries to stick his head out but can't get out. What does he smell? Molasses.

Thursday, October 22, 2015

Tonight's Sky for October 22: Venera 9 Arrives at Venus (1975)

It was on this date in 1975 that the Soviet probe Venera 9 arrived at Venus. While having lost the manned space race, the Russians claimed a major pair of firsts with this mission. First: the orbiter was the first man-made object to orbit Venus and the lander was the first man-made object to return images from the surface of another planet. All told, the lander would operate for 53 minutes and, in addition to pictures, would return valuable data about surface conditions on Venus that were found to be, to say the least, hellish. The orbiter would operate for nearly 2 months, conducting 17 experiments studying the planet's upper atmosphere and acting as a relay for the short-lived lander. 

Wednesday, October 21, 2015

Tonight's Sky for October 21: Orionid Meteors Peak

Tonight will mark the peak of the Orionid Meteor shower for 2015, thus marking the climax for the 2-week event. Every October, Earth passes through the stretch of space junk shed by Comet ######, reaching the deepest concentration of debris tonight. According to some estimates, under ideal conditions (dark country skies), one can expect to see 10-15 meteors per hour. The reason the meteors are called Orionids is because the meteors seem to radiate from the constellation Orion. The best time to view the shower is in the predawn hours, as Orion is at its highest then.

To improve odds of seeing meteors, travel out of the city and to the country if you can. In the suburbs, just going from the front to back yard can make a dramatic difference as this will eliminate glare from those pesky street/house lights to a large extent.

Fortunately, this year's Orionid peak coincides with the First Quarter Moon, which means that nature's night light will be a non-issue as it will have long since set by the time the predawn hours arrive.

Tuesday, October 20, 2015

Tonight's Sky for October 20: First Quarter Moon

Today, the Moon, second brightest object in the sky, has reached the First Quarter phase, which means that it is exactly 90 degrees around its orbit of Earth and is one quarter finished with its current orbit.. 

As for lunar mechanics, the Moon is always half lit. The reason we don't always see it as such is thanks to orientation in relation to us. Right now, with the Moon at a 90 degree angle relative to the Earth-Sun line, we only see half of the lit side.

After today, we will see more of the Moon each night as its lit side turns more toward from us and heads toward Full in a week.