Sunday, August 31, 2014

Tonight's Sky for August 31: Conjunction of Mars, Saturn, and the Moon

Don't have any plans for this evening? Well, good, as there will be quite a sight in the sky worth taking a look at. Tonight and tonight only, Mars, Saturn, and the Moon will be meeting up low in the Southwestern sky at dusk. To see the show, simply head out and look Southwest about an hour after sunset. The Moon, well, it's the Moon. As for the accompanying stars, the reddish one is Mars and the other is Saturn. Cloudy tonight? Well, come tomorrow, the planets will still be there but te Moon will be a good bit higher. 

Saturday, August 30, 2014

Tonight's Sky for August 30: Saturn Sets 3 Hours After the Sun

Saturn is sinking, but don't panic! Tonight, the ringed wonder, which reached opposition on May 10, will now be setting 3 hours after the Sun, meaning that Saturn will be well placed for viewing in the South-Southwestern sky as the sky gets dark. To see Saturn, look low and that bright 'star' is, in fact, the planet Saturn. For more fun, bring out the telescope as even a 60mm department store scope will clearly reveal the planet's rings. Bigger scope? Bigger detail!

Friday, August 29, 2014

Tonight's Sky for August 29: Neptune at Opposition

Today, the planet Neptune, eighth from the Sun, will be at opposition. What does that mean? In short, if viewed from above, the Sun, Earth, and Neptune would be in a straight line in t hat order, with Neptune exactly opposite the Sun in the sky as seen from Earth. End result: Neptune rises as the Sun sets and Neptune sets as the Sun rises. Problem: Neptune is roughly +8 magnitude, which means that you'll need a good star chart and a big telescope to find it. Oh, yes, experience helps a lot, too. 

Thursday, August 28, 2014

Tonight's Sky for August 28: Can You See Mercury?

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 dusk sky immediately after sunset. To see Mercury, scout out a location with virtually no obstruction due West, which is where the speedy planet will pop out of the twilight 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!

Wednesday, August 27, 2014

Tonight's Sky for August 27: 'Young' Moon

How thin of a Moon have you seen? How about one that's just 2 days old and only 4% 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 evening's sky just after sunset.

To see the Moon, you'll need a good Western horizon. How good? One with less than 5 degrees of obstruction. To simulate this, hold your middle three fingers vertically at arm's length to simulate 5 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. The good news, if you have binoculars, you should be good to go, just remember to be patient as the Moon will often appear to suddenly pop into view out of thin air. On the other hand, if you're still looking 30 minutes after sunset, you missed the Moon. 

Tuesday, August 26, 2014

Tonight's Sky for August 26: No Moon

The 24th was Old Moon, the 25th New Moon, which should make the 26th a Young Moon. Well, sort of because the Moon is technically Young today but it will be impossible to see from Earth thanks to the fact that the ecliptic plane is so low relative to planet Earth, which means that the 1% illuminated Moon will be setting less than 10 minutes after the Sun, and thus impossible to see. So, why does this happen?

Again, it all has to do with cosmic geometry, namely the Earth's 23 inclination relative to its axis. This is the same reason we have seasons. In summer, the Earth is tilted away from the ecliptic plane as seen from Earth and in winter, it is tilted towards the ecliptic.

As another interesting observation, the ecliptic and Sun are at opposite extremes in height at opposite times of year, too. 

Monday, August 25, 2014

Tonight's Sky for August 25: 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 us and the Sun, we don't see any of the lit side, thus making the Moon invisible to us as seen from Earth.

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

Sunday, August 24, 2014

Tonight's Sky for August 24: Old Moon Moon is at Apogee

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, now'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. Good luck!

Another point of note: today, the Moon is at apogee, the point in its orbit farthest from Earth. 

Friday, August 22, 2014

Tonight's Sky for August 23: Moon Meets Venus and Jupiter

While Jupiter and Venus have already made their closest pass in the predawn sky at about only a fifth of a degree of angular separation, they're still rather closes and, as an added treat, the waning crescent Moon joins the picture this morning. To see the show, just head out before sunrise and look East, you can't miss it!

Thursday, August 21, 2014

Tonight's Sky for August 21: NASA Loses Communication With Mars Observer (1993)

It was on this date in 1993 that NASA lost contact with its Mars Observer, launched in September, 1992 as the first NASA mission to Mars since the Vikings in 1976. Needless to say, anticipation was high thanks to the nearly 2-decade hiatus for Martian missions. Unfortunately, the mission recaptured interest in NASA for all the wrong reasons (Jimmy Buffett even poked fun at the mission failure in a song) , namely for the reason that the space agency lost communication with the orbiter just days before the planned Mars orbital insertion. However, NASA would soon return to Mars with a series of spectacularly successful missions in the coming decade.

Wednesday, August 20, 2014

Tonight's Sky for August 20: Northern Cross at Zenith at Midnight

Don't have a watch? Well, no problem, at least at midnight as Cygnus, also known as the Northern Cross, is just about at zenith come midnight. To see it, just go out, look straight up, and try and make out the cross-shaped pattern of stars. Hint: bright Deneb, alpha Cygnus, is the top of the cross.

Monday, August 18, 2014

Tonight's Sky for August 19: Jupiter and Venus Still Close

More technical problems fixed . . . and Jupiter and Venus have already made their closest pass in the predawn sky at about only a fifth of a degree of angular separation. However, come the morning of the 19th (tomorrow), they will still be extremely close, as they will be in the next couple of days should tomorrow be cloudy. To see the pairing, just head out before sunrise and look East. Jupiter and Venus are the two brightest objects in the sky and are just about impossible to miss!

Friday, August 15, 2014

Tonight's Sky for August 15: First Extrasolar Solar System

On this date in 2001, scientists announced the discovery of a planet orbiting the star 47 Ursa Major. While not unique in itself (the first extrasolar planet was found in 1995), this was unique in that, with this discovery, 47 Ursa Major became the first star other than the Sun known to have multiple planets. In the intervening years, over 450 multi-planet extrasolar solar systems have been discovered. 

Thursday, August 14, 2014

Tonight's Sky for August 14: The Great Northeast Blackout (2003)

On this day in 2003, millions of people not accustomed to seeing a truly dark sky to see such a spectacle for one most unusual night. Eventually traced to a local failure brought about by trees on power lines in Northeast Ohio, poor power grid design and inadequate warning systems were blamed for the rolling blackout that eventually knocked out power to over 50 million people in 8 states and most of the Ontario province of Canada.

Needless to say, many city-bound astronomers rejoiced at the lack of light pollution.

Wednesday, August 13, 2014

Tonight's Sky for August 13: Perseids Continue

Contrary to what may have been suggested by the non-astronomical media, the Perseid Meteor Shower for 2014 is not over as it continues not only tonight, but for the next week or so. Yes, while the shower peaked last night, it is not like a cosmic faucet gets turned off after the peak. Instead, the meteor is like a rain shower here on Earth in that it gradually starts, peaks, and then tapers off before stopping for the year.

Bottom line: if you couldn't see the shower last night, there's always tonight and the next few though at lessening activity levels. 

Tuesday, August 12, 2014

Tonight's Sky for August 12: Perseid Meteors Peak

Technical difficulties over . . . tonight will mark the peak of the Perseid Meteor shower for 2014, thus marking the climax for the 2-week event. Every August, Earth passes through the stretch of space junk shed by Comet Swift-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 Perseids is because the meteors seem to radiate from the constellation Perseus. The best time to view the shower is in the pre-dawn hours, with 3-6am being best, as Perseus 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.

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

Thursday, August 7, 2014

Tonight's Sky for August 7: Apollo 15 Returns to Earth (1971)

It was on this date that Apollo 15, the 4th successful mission to the Moon, returned to Earth. While Moon missions may have become somewhat seen as routine by this time, Apollo 15 marked a shift in the focus for lunar exploration as this was the first of the 'J' missions, which were focused on science and long-term visits rather than as exploration with science as a side note. Apollo 15 was also notable in that it was the first Apollo mission to use a lunar rover. In all, the astronauts spent nearly 3 days on the Moon with over 18 hours of exploration on the lunar surface itself spread over 3 Moonwalks.

Wednesday, August 6, 2014

Tonight's Sky for August 6: Rosetta Flys By Comet 67P/Churyumov-Gerasimenko

After 10 years in space, t
he big day is finally here for the European Space Agency's (ESA) Rosetta space probe, which is set to enter orbit around Comet Churyumov-Gerasimenko, onto which it will then land a smaller probe, named Rosetta.

If successful, this would be a first off its kind mission because, to date, no probe has ever been landed on a comet before. In contrast, probes have been flown by and deliberately been crashed into comets, most famously NASA's Deep Impact. A soft landing? That's new territory. According to the plan, Rosetta will land on the comet, analyze it with 10 instruments, and even drill into the comet's surface to better determine its composition.  

Tuesday, August 5, 2014

Tonight's Sky for August 5: Mariner 7 Flys by Mars (1969)

It was on this date in 1969 that the Mariner 7 space probe made its close flyby of Mars. Needless to say, fresh off of the Apollo 11 euphoria (the astronauts were still in quarantine), this mission was almost an afterthought at the time despite the fact that the mission was groundbreaking in itself. Flown in conjunction with Mariner 6, the twin space probes would photograph over 20% of the Martian surface, providing a far more complete picture of the Martian surface than did Mariner 4, which returned just two dozen tantalizing pictures of Mars in 1965. Additionally, both probes carried instruments that were vital in studying the composition of the Martian atmosphere and paving the way for future missions to the Red Planet. 

Monday, August 4, 2014

Tonight's Sky for August 4: Cosmic Line Up

If you've been watching the dusk sky to the West lately, you'll have noticed that there have been a lot of rather prominent objects in that direction of late. Tonight, the last good close get-together of four heavenly bodies will present itself. Left to right, you will see the Moon, Saturn, Mars, and Spica. To see the sight, simply go out after the sky starts to dim. 

Sunday, August 3, 2014

Tonight's Sky for August 3: First Quarter Moon Splits Mars and Saturn

A repeat of last night but with a shifted Moon, Mars will now appear to the right of the Moon and Saturn, sixth planet from the Sun, is to the left. For more fun, turn a telescope on Saturn.

Saturday, August 2, 2014

Tonight's Sky for August 2: Moon Splits Mars and Spica

Tonight (and tomorrow) will bring easy to spot pairings of prominent astronomical objects. Tonight's feature: the waxing crescent Moon will split the planet Mars and star Spica. To see the sight, simply go out after the sky starts to darken and look for the Moon. The blue star to the right is Spica, alpha Virgo, and the red 'star' is actually the planet Mars, fourth from the Sun. As an interesting additional activity, look at and contrast the colors of Mars and Spica. Yes, while not like Christmas lights, the color difference is clear when two astronomical bodies of contrasting colors are close to each other.

Friday, August 1, 2014

The August Sky

As August dawns on us, the nights are finally starting to get longer again in a noticeable manner. As we approach another equinox, the loss of daylight (and thus the gain of dark) will accelerate once again. During the course of the month, we will lose about 1 ½ hours of daylight, which, combined with even earlier rise times of the summer favorites, makes for good times of astronomical proportions.

Cool Constellations
With the advent of August, the spring constellations are rapidly saying goodbye, with Virgo the next major constellation to disappear. Also getting low in the Southwest is Libra and Bootes and Corona are now just about due West at nightfall. In the North, the Big Dipper continues its dive, flattening out as it starts to approach the horizon. Perhaps the best part of the August sky is that one doesn't need to stay up overly late to see all the best sights of summer. At nightfall, Hercules is still near zenith, the Summer Triangle (Lyra, Cygnus, and Aquila along with hangers-on Saggita and Delphinus) is at zenith, Scorpius is due South with Ophiuchus and Sagittarius on either side, both still well-placed for observing. Also, the Milky Way is at its best positioning right after nightfall, too. For people who like to stay up late (or get up extremely early) a fall preview in the form of Pegasus, both Pisces, Cetus, Andromeda, Aries, Capricorn, Aquarius, and even Perseus is on tap in the wee hours of the morning while, by month's end, the bright stars of winter in the form of Orion, Auriga, Taurus, and Gemini are visible, too.

Planetary Perceptions
In terms of planets, August isn't shaping up to be all that great of a month despite 4 of the 5 classical planets being visible. Why? All of the visible planets are rather close to the Sun. Starting in the evening, both Mars and Saturn are visible, though time to catch them under truly dark skies is minimal even if you have a low Western horizon. For most of us, though, these two planets, especially Mars, will be dusk objects from the backyard. In the predawn sky, Venus is still rather well-placed at month';s start but, nothing being forever, this exceptionally long apparition of Venus will be starting to come to a conclusion in August as the planet begins a dramatic drop toward the Sun's glare as the month unfolds. On the other hand, Jupiter, which just reappeared from behind the Sun as a morning planet late last month continues its rise out of the solar glare but still remains rather low in the Eastern predawn sky. Mercury? Well, it will make a dusk appearance starting mid month but, thanks to the angle of the ecliptic plane, it's about as bad as an appearance as is geometrically possible, barely popping over the Western horizon.

And let's not forget . . . 

Tonight's Sky for August 1: Lengthening Nights
We are now about half way into summer, as in nearly 45 days past the Summer Solstice, which features the shortest night of the year. By now, half way between the Summer Solstice and Vernal Equinox (12 days of day and 12 of night), the nights are obviously getting longer as the sunrises come later and the sets earlier. Throughout the month, the length of the night will increase dramatically, which stands in stark contrast to June and July.