Close Encounter with Mars

Jan 26, 2010 by Dr. Tony Phillips
The full Moon and Mars converge in the constellation Cancer on Jan. 29th.

It rises in the east at sunset, pumpkin-orange and brighter than a first magnitude star. You stare at it, unblinking. Unblinking, it stares right back. It is Mars.

This week Earth and Mars are having a close encounter. On Jan. 27th, the Red Planet will be only 99 million kilometers away and look bigger through a telescope than at any time between 2008 and 2014. The planet's 14-arcsecond diameter will remain essentially unchanged for another week or so, setting the stage for some good observing.

"Mars is an excellent target for all backyard telescopes right now," reports amateur astronomer Joel Warren, who sends these pictures from his observatory in Amarillo, Texas:

"The planet's North Polar Cap was brilliant in my 11-inch reflector," he says.

And because summer is coming to the Martian north, the bright polar cap and its icy-blue clouds are shifting, sublimating and changing every night. It's a lively show for anyone with a mid-sized telescope and a digital camera.

But a telescope is not required to enjoy the show. Mars is a pleasing sight even to the unaided eye. With a visual magnitude of -1.3, it is almost as bright as Sirius (magnitude -1.44), the brightest star in the sky.

Compare the two—Sirius vs. Mars. They are in the same patch of sky all week long. While Sirius is as blue as the tip of an acetylene torch, Mars looks more like the ruddy head of a lit match. The contrast is beautiful.

Another fun comparison: Sirius twinkles but Mars does not. Distant, pinprick stars are more disturbed in their appearance by tiny irregularities in Earth's atmosphere than nearby, disk-shaped planets. Compared to the dancing light of a star, Mars has a smooth, unblinking glow.

For visual observers, the best display comes on Friday, Jan. 29th, when the and Mars converge for a floodlamp-bright conjunction. On that night, Mars will be at opposition—i.e., directly opposite the sun. It will rise alongside the at sunset and soar overhead at midnight, never straying more than about 6o from the first full Moon of 2010. (Note: Contrary to "Mars Hoax" emails, Mars will not be as wide as the full Moon. To the unaided eye, Mars will resemble a bright orange star.)

Earth and Mars have close encounters approximately every 26 months. Some are closer than others, however. In 2003, the Earth-Mars distance was only 56 million kilometers, a sixty-thousand year minimum. The whole world stopped to watch as news reports trumpeted the event. This year's gulf is almost twice as wide, and professional astronomers do not consider it a particularly remarkable encounter.

Don't let that stop you. is near. Take a look!

Explore further: SpaceX will try again Fri. to launch station cargo

Provided by Science@NASA, by Dr. Tony Phillips

4.8 /5 (6 votes)

Related Stories

Moon, Mars bright lights in the big sky

Dec 24, 2007

The moon and Mars -- not the stars -- emitted enough wattage Monday to providing night travelers by sleigh and by foot a lighted way to their destinations.

Mars Doubles in Brightness

Nov 22, 2007

During the past month, Mars has doubled in brightness and it is putting a nice show for backyard stargazers.

Hurtling Toward Mars

Aug 21, 2007

By the time you finish reading this sentence, you'll be 25 miles closer to the planet Mars.

Mars makes a special appearance

Nov 01, 2007

All five of the planets visible with the unaided eye will be on display during November nights, but the special attraction will be Mars. The red planet is approaching Earth in its orbit, and it won't appear ...

Recommended for you

Let's put a sailboat on Titan

3 hours ago

The large moons orbiting the gas giants in our solar system have been getting increasing attention in recent years. Titan, Saturn's largest moon, is the only natural satellite known to house a thick atmosphere. ...

Image: Rosetta's Philae lander snaps a selfie

3 hours ago

Philae is awake… and taking pictures! This image, acquired last night with the lander's CIVA (Comet nucleus Infrared and Visible Analyzer) instrument, shows the left and right solar panels of ESA's well-traveled ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

baudrunner
not rated yet Jan 27, 2010
I am a Cancer and my birthday is exactly six months from Jan 27, in June. I was also born in the middle of the night under a full moon.

I am buying a lottery ticket.

More news stories

Let's put a sailboat on Titan

The large moons orbiting the gas giants in our solar system have been getting increasing attention in recent years. Titan, Saturn's largest moon, is the only natural satellite known to house a thick atmosphere. ...

ESO image: A study in scarlet

This new image from ESO's La Silla Observatory in Chile reveals a cloud of hydrogen called Gum 41. In the middle of this little-known nebula, brilliant hot young stars are giving off energetic radiation that ...

Progress in the fight against quantum dissipation

(Phys.org) —Scientists at Yale have confirmed a 50-year-old, previously untested theoretical prediction in physics and improved the energy storage time of a quantum switch by several orders of magnitude. ...