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Night Sky News: Primetime for Mercury, Venus Duo and Asteroid Close Call

The moon is the natural starting point when learning to navigate the night sky but once you become familiar with its craters and mountain ranges it’s time to go beyond lunar orbit. Mercury and Venus the two innermost planets in the solar system are hundreds of times farther but offer up fairly easy naked eye and binocular targets- and this week is the perfect time to hunt them down in the evening sky.

Until mid November look very low in the southwestern sky, about 30 minutes to an hour after local sunset for two stars – and third much fainter one  easily visible through binoculars. The two stars you will most likely see with unaided eyes are white Venus – which is the brightest, and Mercury. The two worlds will be quite close in the sky and appear to be separated by only 2 degrees – that’s only about the width of your thumb at arm’s length.

In between these two planets you will find  a fainter orange star Antares.  On November 10th the  three cosmic amigos will appear to be in a near perfect vertical line-up in the sky – quite a cool sight with binoculars.  Of course the trio’s close encounter is just an optical illusion since the two planet are separated by nearly 68 million km and Antares lies a whopping 600 light years from our solar system.

The three evening stars will begin to go their own ways soon and you’ll find that as the days go on Venus will slowly creep higher in the early evening sky, increasing its distance from the Sun so that the planet’s own setting time after sunset increases from an hour in early November to nearly two hours at the end of the month.

NASA animation showing asteroid 2005YU55 orbital path near Earth on November 8-9, 2011. NASA / JPL

Skywatching Extra: Earth will be buzzed by a 400 meter wide asteroid 2005 YU55 this Tuesday, November 8th at 6:28 pm ET when it passes within 319,000 km from Earth – about three-quarters’ the Earth – Moon distance.

While there is no danger of collision whatsoever this time around astronomers will use this unique opportunity to study the space rock up close using professional telescopes. Backyard stargazers can also keep watch if they have at least a mid-sized  6 to 8 inch telescope.

According to Sky and Telescope magazine, expectations are that it will shine at about 11.1 magnitude – which is 100 times fainter than the faintest star the human eye can see. The asteroid will be going at a quick pace through the overhead sky, buzzing through nearly the half of the overhead evening sky – from constellations Aquila to Pegasus – in no more than 10 hours.  That’s so fast that you can watch it chug along in real time as it appears to traverse the entire field of view a low power eyepiece of a telescope in about 5 minutes. That is crazy quick when it comes to observing moving celestial objects.

General finders skychart for asteroid 2005YU55. Click image for hi-res version. Courtesy of Sky & Telescope magazine


So,  if you are up for a super cool observing challenge then I recommend you start with grabbing a copy (PDF)  of detailed version of the finders sky chart above and get under the stars Tuesday with your trusty telescope. . Good luck with your hunt!


Andrew Fazekas, aka The Night Sky Guy, is a science writer, broadcaster, and lecturer who loves to share his passion for the wonders of the universe through all media. He is a regular contributor to National Geographic News and is the national cosmic correspondent for Canada’s Weather Network TV channel, space columnist for CBC Radio network, and a consultant for the Canadian Space Agency. As a member of the Royal Astronomical Society of Canada, Andrew has been observing the heavens from Montreal for over a quarter century and has never met a clear night sky he didn’t like.


  1. […] A robotic telescope on the Canary islands, off the coast of West Africa will be tracking the asteroid 2005YU55 as it zips by Earth tonight (Nov.8) and you can watch along from the comfortable confines of your home starting at 4 pm ET. So if you are clouded out or don’t have 6 inch or larger telescope this is the next best way to witness this close asteroid flyby.Remember that the closest encounter will be at 6:28 pm Eastern Time, but the asteroid is expected to be visible for many hours thereafter as its surface gets lit up by the sun, offering great views through larger telescopes. For a viewer’s guide check out my National Geographic story. […]

  2. Juan Perez Monsalvo
    November 8, 2011, 10:41 am

    Will it be visible from Argentina? More specifically Buenos Aires, if so at what time and where in the sky?

  3. Uma Maheshwari
    Bangalore, India
    November 8, 2011, 4:11 am

    When can we see in Bangalore, India

  4. […] (Get more tips on how to see 2005 YU55, including a sky chart with the asteroid’s path.) […]

  5. […] If you have clear skies Tuesday night, know your way around the sky, and have a big enough telescope you can actually spot this interloper zip across the starry skies. Check out my quick viewer’s guide to the asteroid pass and upcoming views of Venus and Mercury… […]