Friday, February 27, 2015

Tonight's Sky for February 28: Be Alert for Aurora

Tonight, NOAA is predicting as high as a 60% chance of aurora (also known as Northern Lights) for people living at high latitudes. Though there is no appreciable solar activity at the moment, the Earth is set to pass through a fold in the heliospheric current sheet, which can result in a display. Needless to say, if you live at a high latitude and the sky is clear, keep an eye on the sky tonight. 

Tonight's Sky for February 27: Cosmic Soccer, Pollux?

Tonight, there will be a bit of cosmic soccer, of sorts, as the Moon will be parked right next to the cosmic twins, Gemini, and more specifically, next to the foot of Pollux, the lower of the twins as seen when the constellation is just starting to rise in the East. As a second activity, if you have a telescope handy, turn it on Castor, the other twin as it is a binary (multiple) star system and see how many of the companion stars you can spot. For the record, Castor is a 6-star system. 

Tuesday, February 24, 2015

Tonight's Sky for February 24: 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 will be making its best appearance of the fall this morning.

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 never gets very far away from the Sun. As a result, Mercury is often obscured from view by the Sun's glare.

As of today, Mercury 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 and making its best morning appearance of this orbital cycle. While not the best appearance, (30 minutes before sunrise, Mercury is only about 5 degrees up from the horizon), t his offers the best chance to catch Mercury in t he morning for awhile. To simulate, hold your fist vertically at arm's length and then halve it.

So, take a moment or two, go out just before dawn, 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, February 23, 2015

Tonight's Sky for February 23: First Naked Eye Supernova in Almost 400 Years (1987)

It was on this date in 1987 that the Earth was treated to the first supernova visible to the naked eye in nearly 400 years. Officially dubbed supernova 1987A, the stellar explosion, located in the Large Magellanic Cloud, peaked at a brightness of magnitude +3 in May and would remain visible into late summer.

Before this event, the last naked eye core collapse supernova observed was in 1601 and studied by, most notably, Johannes Kepler. To date, Kepler's Supernova is the last core collapse supernova observed within the Milky Way. Though not as bright, 1987A provided a lot of insight to scientists about the nature of these events. First: the star that exploded was a blue supergiant, a class of star that was previously thought to be stable, like our Sun (but only much, much bigger).Another insight: stars about to go supernova emit a wave of neutrinos before they explode, thus serving as a method to detect them a few hours before light from the actual explosion can be seen. 

Sunday, February 22, 2015

Tonight's Sky for February 22: Venus and Mars Extremely Close

This is the view, sans Moon.

Tonight and tomorrow night, Mars and Venus, fourth and second planets from the Sun, will be within a degree of each other. To see the show, go out just after sunset and scan the West-Southwest sky along the horizon with binoculars. The brighter 'star' is Venus and the dimmer is Mars. If you're clouded out, don't worry, the planets will remain close the next few nights. 

Friday, February 20, 2015

Tonight's Sky for February 20: Venus, Mars, and Moon

Tonight just after sunset, the Moon, Mars, and Venus will be making a close pass low in the Western sky just after sunset. To see the shoe, just go out and look West after the Sun goes down. The Moon? That's impossible to miss. Moon found, look for two bright stars (binoculars recommended) very close to it. The brighter one is Venus and the dimmer Mercury. As close as the planets are tonight, they will b even closer the next few nights . . .  

Wednesday, February 18, 2015

Tonight's Sky for February 18: 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, e 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.

Monday, February 16, 2015

Tonight's Sky for February 16: Explorer 9 Launched (1961)

It was on this date in 1961 that Explorer 9 was launched into orbit from the Wallops Flight Facility, making the first successful orbital launch from that location. As for the probe itself, it was designed to study the Earth's upper atmosphere and became the first such successful research probe on account of previous failures of similar missions.

Sunday, February 15, 2015

Tonight's Sky for February 15: the Chelyabinsk Meteor Explosion (2013)

It was on this date in 2013 that the Siberia was rocked by a meteor explosion near the city of Chelyabinsk. The best part: thanks to the profusion of photographic technology, the incoming fireball as bright as the Sun and explosion (even brighter) was captured from numerous sources at the time and immediately following the event.

As for what took place on the ground, over 1,000 people were injured, mainly from shattered window glass caused by the explosion's shock wave. Some people even suffered concussions. Just how powerful was the blast? A magnitude 6 Earthquake was recorded over the area as a result of the explosion.

Vital stats for the meteor? It was about 50 feet across, weighed about 7,000, and released the energy of about 300 kilotons of TNT when it exploded about 7-15 miles in the air while traveling at a speed of about 40,000 mph. For the record, the Hiroshima bomb exploded with the force of about 16 kilotons, or about only 1/20th as powerful as the Chelyabinsk meteor.

And in cosmic terms, this meteor was tiny . . . 

Saturday, February 14, 2015

Tonight's Sky for February 14: The Pale Blue Dot (1990)

It was on this date in 1990 that Voyager 1's narrow angle camera was turned around and pointed towards Earth, which was, at the time, more than 3.7 billion miles distant. The image, which contains 640,000 pixels (this was 70s technology), captured Earth as a tiny pinpoint of light on 3 images, which were combined to create the final picture (each sub image was shot in the red, green, and blue). As for Earth, it takes up approximately 0.12 of a pixel, or roughly 1/6,400,000th of the image.

The impetus for the image: a request from the now legendary Carl Sagan, who used his description of the Earth as a “pale blue dot” as the title for a 1994 book of the same name. Of the image and its significance, Sagan states that:

From this distant vantage point, the Earth might not seem of any particular interest. But for us, it's different. Consider again that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.

The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that in glory and triumph they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner. How frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity – in all this vastness – there is no hint that help will come from elsewhere to save us from ourselves.

The Earth is the only world known, so far, to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment, the Earth is where we make our stand. It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another and to preserve and cherish the pale blue dot, the only home we've ever known.”

-Carl Sagan

Makes you feel kind of insignificant, doesn't it?

Thursday, February 12, 2015

Tonight's Sky for February 12: Still Possible to See Double

With the longest nights of the year upon us (but now shortening), this is the time when you can see the same star twice in one night, as is on the set in the evening and on the rise in the morning. Despite this being the first month of winter, the summer stars are still visible in the sky at dusk. The stars of the Summer Triangle make perfect targets because of their brightness. As for what to do, simply go out and observe the stars of the Triangle. That done, either go to bed or stay up and enjoy the night until just before sunrise. At that point, go out and look in the Northeast for your chosen star's return to the sky. How many people can say they saw the same star twice in one night that way?

Wednesday, February 11, 2015

Tonight's Sky for February 11: 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 a new lunar cycle.   

Tuesday, February 10, 2015

Tonight's Sky for February 10: Saturn Rises 5 Hours Before the Sun

Anyone wanting to view Saturn of late has not had much luck thanks to the ringed wonder's close proximity to the Sun. However, things are getting better. This morning, Saturn will be rising five hours before the Sun. To see Saturn this morning, go out just before sunrise and look South. If it is clear, you will see a bright yellow 'star' that, is in fact, the ringed planet.

Monday, February 9, 2015

Tonight's Sky for February 9: Can You See Mercury Yet?

You may have noticed that there was little mention of Mercury, first planet from the Sun all month. Why? Well, it simply isn't making that great of an appearance this month. It is, however, up (barely) in the dawn sky immediately before sunrise. To see Mercury, scout out a location with virtually no obstruction due East, which is where the speedy planet will pop out of the predawn sky. How low will you need to look? About three degrees up from the horizon. To simulate, a little finger held at arm's length spans about a degree of sky. Needless to say, binoculars are a must!

Sunday, February 8, 2015

Tonight's Sky for February 6: Jupiter Reaches Opposition

Tonight, the planet Jupiter, fifth from the Sun, will be at opposition. What does that mean? In short, if viewed from above, the Sun, Earth, and Jupiter would be in a straight line in that order, with Jupiter exactly opposite the Sun in the sky as seen from Earth. End result: Jupiter rises as the Sun sets and Jupiter sets as the Sun rises, meaning that Jupiter is up all night. 

Wednesday, February 4, 2015

Tonight's Sky for February 5: Moon Meets Regulus

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

To see Regulus, just go out before sunrise and look for the Moon, which is impossible to miss. As for Regulus, it's that bright blue star right next to Luna.

Tonight's Sky for February 4: Venus is Setting 2 Hours After the Sun

Anyone wanting to view Venus of late has not had much luck thanks to the ringed wonder's close proximity to the Sun. However, things are getting better. This morning, Venus will be setting two hours after the Sun. To see Venus this evening, go out just after the sky starts to dim in the evening and look West. If it is clear, you will see a bright yellow 'star' that, is in fact, the planet.

Tuesday, February 3, 2015

Tonight's Sky for February 3: 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. 

Monday, February 2, 2015

Tonight's Sky for February 2: Happy Groundhog's and Cross-Quarter Day

Today is Groundhog's Day and also a cross-quarter day. What is a cross-quarter day? It's the mid way point of any season and was, like the solstices and equinoxes, an important time for early civilizations as these days served as another natural way to divide up the year into periods of time, which became a matter of life and death with the advent of large scale agriculture around 5000BC. 

Sunday, February 1, 2015

The February Sky

With new month of February upon us, the lengthening of the days will be noticeable at the start and plainly obvious by month's end as we get closer and closer to the equinox, which will come on March 20. Besides the rapidly lengthening days (and thus, shortening nights), February marks the last full Month of Standard Time, with DST returning the first Sunday of next month. All in all, there should be a sense of urgency to get out and see the sky, especially if you live in a location dominated by clouds during the winter.

Cool Constellations
By nightfall in February the fall constellations are all extremely low in the Western sky by nightfall. Hint: don't dilly dally when it comes to viewing them, they'll be gone by month's end. In the Northwest, ‘W’-shaped Cassiopeia is still high up, house-like Cepheus is low, and the mythological hero Perseus Is still reasonably well-placed for early evening viewing. Moving away from the past and into the present celestial landmarks for this time of year, the Big Dipper is perpendicular to the horizon by the time the sky gets dark and things will only be getting better for Dipper fans as the next few months go along. Almost at zenith is the bright Capella, alpha Auriga. The cloudy patch that is the Pleiades is also very high come nightfall this time of year, as is the V-shaped Hyades cluster. Looking in the South, you'll see all the winter favorites like unmistakable Orion, 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. Aldebaran is also right in the midst of the Hyades. 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 the Summer Triangle along with the front half of Scorpius, highlighted by fiery red Antares, the rival of Mars.

Planetary Perceptions
Like January, February is looking to be another 5 for 5 planet month.. At dusk, Earth's two planetary neighbors, Mars and Venus, will be engaging in a cosmic meet-up come mid month,. Culminating in the February 21-22 conjunction, which will see both planets within a degree of each other. As for longer trends, Venus will continue to climb out of the dusk twilight while Mars stubbornly hangs low in the Southwest, setting roughly 2 ½ hours after the Sun all month long. Moving later into the night, Jupiter is up all night as it reaches opposition (directly opposite the Sun as seen from Earth) on the 6th. Additionally, Saturn continue to re-emerge from the Sun in the predawn sky. By month's end, the ringed wonder will be just about due South at dawn. Last but not least, speedy Mercury, which reached greatest elongation in mid January and quickly dropped out of the dusk sky shortly thereafter, will be back starting in early February and reaching greatest elongation in the predawn sky around the 22nd. Unfortunately, thanks to the flattening ecliptic, the little planet will be nowhere near as high as it was last month.

Tonight's Sky for February 1: Columbia Disaster (2003)
It was on this date in 2003 that the space shuttle Columbia, first of the shuttle fleet disintegrated upon reentry, killing the crew of 7 astronauts.

At the time of the Columbia's flight, there was a growing chorus of whispers suggesting that the space shuttles were ending their useful lives and needed to be retired. When development began in the early 1970s parallel with Skylab, the space shuttles were (and arguably still are) the most complex machines ever built. Shoved to the back burner to focus on Skylab, the shuttles became top priority in the late 1970s and early 80s. Finally, in 1981, Columbia made the first orbital flight. In the following years NASA would add 4 more shuttles. Aside from the Challenger disaster in 1986 (which could have been avoided if NASA management had listened to the engineers), the shuttles performed flawlessly, which is how Columbia's final mission went until the crucial re-entry phase, during which the shuttle disintegrated, killing the crew, and scattering thousands of pieces of debris across a stretch of the American South hundreds of miles long. After a months-long investigation, it was determined that a piece of insulating foam had broken away from the main fuel tank, impacted Columbia's wing, and dislodged some of the thermal tiles used to protect the shuttle from the extreme heat of reentry. The result: the heat caused by friction of the Earth's atmosphere at the high speed of atmospheric reentry caused the shuttle's hull to fail and the craft to disintegrate.

Following the Columbia disaster, the whispers about retiring the shuttle turned to shouts. The following year, President Bush called for the creation of the Constellation Program and a return to the Moon. The chosen craft for Constellation: rockets, which are nowhere near as complex as the shuttles. Shortly thereafter, it was announced that the shuttles would be retired. Finally, on July 26, 2005, Discovery made the first post-Columbia flight (Discovery also made the return flight after Challenger). For these final missions, post-launch inspections of the shuttles' underbellies and heat tiles were mandatory. Still, old as they were, the shuttle fleet continued to perform admirably, so much so that there was an intense lobbying effort to keep them flying until a replacement craft for manned spaceflight became operable.