• The 'Comet of the Century' ... and other night-sky highlights for 2013

    David Lillo / AFP - Getty Images

    Comet McNaught shines above Chile in 2007. Will Comet ISON be as bright in 2013?

    By Alan Boyle, Science Editor, NBC News


    Next year's most eagerly awaited shows in the skies above might not happen — but that's exactly what makes them so eagerly awaited. There's nothing like uncertainty to build up the drama, and right now, Comet PANSTARRS and Comet ISON are surrounded by bright haloes of uncertainty.

    The picture should be getting clearer in the weeks ahead for the comet formally known as C/2011 L4 PANSTARRS, which was discovered in 2011. It'll take a few more months to get a fix on C/2012 S1 ISON, which was first spotted this September. All we can say right now is, if the comets live up to their current high expectations, PANSTARRS could blaze as bright as Venus in March — and then, in November and December, ISON could outshine the moon to the "Comet of the Century."

    "If Comet ISON can survive perihelion passage ... then we are almost surely in for a striking display in the morning sky as Comet ISON recedes from the Sun next December," veteran observer John Bortle said this month on the Comets Mailing List. "Its immense tail, partly the result of our extremely favorable viewing circumstances in this case and just as with the Great Comet of 1680, could well result in a tail of amazing length and surface brightness, even if tipped by only tiny, relatively insignificant head."

    The best part is that these comets will be visible in the Northern Hemisphere, unlike the spectacles created by Comet McNaught in 2007 and by Comet Lovejoy a year ago. Why let the Southern Hemisphere have all the fun?

    PANSTARRS and ISON are just two of the highlights coming up for skywatchers next year. Here's my top-10 list for 2013, plus some bonus picks from Space.com skywatching columnist Joe Rao:

    Jan. 2-3 for Quadrantid meteors: If the weather's clear, the Quadrantid meteors should put on serviceable show this year. The Quadrantids are sparked by debris from asteroid 2003 EH1, and appear to emanate from an area of the sky known as Quadrans Muralis, around the northern tip of the constellation Bootes. The peak rate is expected to reach 80 meteors per hour, but the glare of a waning gibbous moon could interfere somewhat. "Unlike the more famous Perseid and Geminid meteor showers, the Quadrantids only last a few hours, so it's the morning of Jan. 3 or nothing," NASA says. Check out NASA's Quadrantids website for a video feed on the nights of Jan. 2-4.

    April 25 for partial lunar eclipse: Three eclipses of the moon are coming during 2013 — and although none of them will be spectacular, they're worth keeping an eye on if you're in the right place. The April 25 partial eclipse will be visible from Europe, Africa, Asia and the Pacific. The other two lunar eclipses are a nearly imperceptible hint of a penumbral eclipse on May 25, and a somewhat deeper penumbral eclipse on Oct. 18-19 (visible, at least in part, from the Americas, Europe, Africa and Asia). Even if you miss seeing these eclipses with your own eyes, there'll be plenty of photo galleries showing the moon in its best light.

    March for Comet PANSTARRS: The comet is due to streak past Earth on March 5 and make its turn around the sun, known as perihelion, on March 9-10. The prime time for observers at mid-northern latitudes will come after perihelion, when PANSTARRS will be visible in the evening sky. On March 12, the comet is expected to share the sunset's afterglow with a beautiful crescent moon.

    Issei Kato / Reuters file

    Clouds cast a pall over an annular solar eclipse as seen from Hirai Daini Elementary School in Tokyo on May 21, 2012. An annular eclipse is due to occur on May 10, 2013, and in November there'll be a hybrid eclipse that morphs from annularity to totality.

    May 9-10 for annular solar eclipse: A "Ring of Fire" eclipse will roll across Australia, Papua New Guinea and the South Pacific, with a partial solar eclipse visible from a wider swath of the Pacific. If past history is any guide, some of us in North America will be watching the event unfold on the evening of the 9th, via webcasts from the scene. 

    May 24-28 for planetary party: Mercury, Venus and Jupiter mix it up in western skies over a series of nights in May, with Saturn and the moon adding their shine. The main event may well be the Venus-Jupiter conjunction on May 28 — but it won't be as spectacular as the double-planet feature we saw in February, because this one will take place so soon after sunset. 

    June 23 for Supermoon: The moon goes full just after this year's closest approach to Earth, meaning that it'll look 14 percent bigger and 30 percent brighter than it does at maximum distance. Last May's Supermoon made such a splash that I suspect this could turn into an annual moon-watching event. 

    Aug. 11-13 for Perseid meteors: Annual meteor showers have their ups and downs, and the advance word is that 2013 will be an "up" year for the Perseids. The moon will be a mere crescent in the morning sky, cutting down on the glare. The flux of shooting stars is expected to be normal, peaking at around 100 meteors per hour.

    Oct. 12 for moon observation: International Observe the Moon Night provides an opportunity for veteran skywatchers to show you the moon at its best — no, not during the full moon, but during the first-quarter phase. That's when you can get a good look at the moon's craters and shadowy mountains. Check in with the InOMN website for updates.

    Nov. 3 for hybrid solar eclipse: This hybrid is a strange one, starting out as an annular "Ring of Fire" eclipse and turning into a total eclipse as the moon's shadow races across the planet. The track of annularity-totality runs across the Atlantic, goes through the middle of Africa and ends up in Somalia. If you can't afford a cruise or an expedition, keep a watch on the webcasts.

    November-December for Comet ISON: Will ISON shine "brighter even than the full moon" a year from now? That seems hard to believe right now, but by next autumn, astronomers should have a good idea just how much of a phenomenon the comet could turn into. NASA's Curiosity rover may be able to snap a picture when ISON passes by Mars in September, and it could become visible to the naked eye in October. It's due to come well within a million miles of the sun at perihelion on Nov. 28 — and that will be the most dramatic moment for skywatchers. Some comets, like last year's Comet Elenin, break up when they slingshot around the sun. Others, like Comet Lovejoy, survive the encounter spectacularly. If ISON lucks out, we could well be raving about the Great Christmas Comet of 2013 by this time next year. (Just don't believe anyone who tells you it's a doomsday comet.)

    Bonus round: Over at Space.com, Joe Rao's "13 must-see stargazing events for 2013" also include a close conjunction of the moon and Jupiter on Jan. 21, great evening views of Mercury from Feb. 2 to 23, and a holiday show featuring Venus in December. And don't forget the northern lights: Although auroral displays are hard to predict, the height of the sun's 11-year activity cycle should bring some great light shows to Earth's higher latitudes in 2013. 

    Update for 8:50 p.m. ET: British educator-astronomer Stuart Atkinson has set up a blog titled "Waiting for ISON" to monitor the comet countdown. Atkinson is also in charge of "The Road to Endeavour" blog about the Opportunity rover on Mars; and The Gale Gazette, which keeps tabs on NASA's Mars Curiosity mission.

    More about the coming comets:

    Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

  • See the eclipse in style

    msnbc.com

    A lunar eclipse occurs when the sunlit moon moves through Earth's shadow. Click here for an interactive graphic that explains eclipse astronomy.

    If you live in the Americas, you'll have to get up early on Saturday morning to catch a glimpse of a partial lunar eclipse - but this one should look bigger than you'd expect, thanks to a trick of the eye.

    This lunar eclipse is actually the second event in this year's eclipse parade, and arguably the least spectacular blackout of the bunch. The really big events are coming up ... including an exotic total solar eclipse next month and a perfectly timed lunar eclipse in the midst of the December holiday season.

    The heart of Saturday's eclipse won't even be visible from parts of the East Coast. But the fact that it takes place close to sunrise means the eclipsed moon will be low in western skies as seen from the rest of the United States - and that means the well-known "moon illusion" will come into play.

    The moon always looks bigger when it's near the horizon, as compared with when it's high in the sky. But the reasons for that are still a matter of debate among psychologists: One factor is that the moon's proximity to the horizon leads the viewer to see it alongside tiny distant objects on the horizon. Our primate brains are programmed to perceive the moon as being even farther away, and much bigger than those distant objects.

    But when the moon is hanging in a big empty sky, our brains don't make that perceptual connection quite as easily. Some researchers say we perceive the heavens as a shallow inverted bowl, with celestial objects high in the sky seeming to loom more closely, like a cloud or a bird directly overhead. Others say the "inverted bowl" theory is dead-wrong, and say the angular-size illusion involves something called oculomotor micropsia.

    For more perspectives on the moon illusion, check out these archived explanations from NASA Science News, Space.com and Bad Astronomy - and ponder the mystery as you gaze at the morning's darkening moon.

    Eclipse course

    Sky and Telescope

    This chart shows the progression of Saturday's partial lunar eclipse, with times expressed as UTC (GMT). The peak of the event comes at 11:38 UT, which is 7:38 a.m. ET (after sunrise) or 4:38 a.m. PT.

    Here are a few more tips to add some style to your moon observations:

    • Because Earth's shadow covers only about half of the moon at the most, this eclipse won't be as spectacular as totality, but you may see a slight reddening of the dark half, due to the light refracted by Earth's atmosphere, as explained in this article.

    • The peak of the eclipse comes at 7:38 a.m. ET - after the sun has risen - but for West Coast residents that's a doable 4:38 a.m. Prime time comes even earlier in the Pacific and east Asia - with Australia potentially the most pleasant place for eclipse-viewing. (Put a shrimp on the barbie for me Saturday evening, mate!) For the full details on viewing conditions, click here.

    • This weekend is a good time to look for the International Space Station in the skies above. In fact, the shining orbital outpost is due to make a pass over the United States right around the time of the eclipse. Check out NASA's online sighting database to find out when you'll be able to spot it. Click onto SpaceWeather.com for more about space station sightings as well as pictures of the eclipse and this month's auroral displays.

    • This eclipse is a mere warmup for the big South Pacific solar total eclipse that's due to occur on July 11. The bad news is that I won't be going to Easter Island to watch the show in person. The good news is that you can usually find a webcast to watch totality in real time, even if it's the middle of the night where you live. Stay tuned for a rundown of the viewing opportunities.

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