Mars closest to Earth December 18
The red planet, Mars.
Tuesday, December 18, 2007
Tonight, the planet Mars will come closest to Earth for all of 2007.
At a distance of about 88 million kilometers – or 55 million miles – this will be Mars’ nearest approach to our planet until the year 2016. But, no, Mars will not now or ever appear as large as the full moon – as has been erroneously reported in a widely circulated e-mail hoax.
It’s true that Mars now appears largest in our sky until 2016. But the diameter of Mars is still less than one one-hundredth that of the full moon as seen from Earth. If you could see them side by side in space, you’d find that Mars’ true diameter is about twice that of moon. So Mars would have to be twice the moon’s distance to look the same size. It’d have to be about 800 thousand kilometers – 500 thousand miles – away to appear as big as the full moon.
And again Mars is closest tonight until 2016 at 55 million miles away. Tonight, Mars at its closest looks like an exceptionally brilliant reddish “star.” You can tell that it’s Mars, because this ruddy planet shines with a much brighter and steadier light than the twinkling stars. Look for Mars in the east at nightfall.
According to the mathematical wizard Jean Meeus, Mars will be closest to Earth on December 18, at 11:45 p.m. Universal Time. For the Central Time Zone in the United States, that converts to 5:45 p.m. tonight (Dec. 18).
Because of Mars’ nearness to Earth right now, many telescopes will be pointing at the red planet in December and January. Be forewarned. It takes a lot of patience and persistence to find Mars’ surface features through a telescope. At times, Earth’s atmosphere isn’t steady (twinkling stars indicate atmospheric turbulence) and Martian dust storms sometimes obscure the view. Knowing what filters to use on the telescope is also a plus. Looking at Mars is – at best – a tantalizing experience.
Astronomy clubs and observatories near you may be hosting public viewings of Mars around now:
Observatory Search: United States
Interested in seeing planets and its movements. Well,your article is informative to a common man like me. Thanks
S Dandapani
Santhanam,
Thank you for sharing your comment with Earth & Sky. We aim to present the subject matter clearly and understandably. If we don’t quite succeed in our quest, we encourage our visitors to ask questions and to seek clarification.
Best Wishes,
Bruce
I have recently picked up astronomy and have been studying the stars with a pair of (recommended) 20×80 binoculars (and with help from this site). However, I’m a bit confused. One page on the site claims that on 12/18, Mars will be closest to Earth. BUT on another page it declares 12/24 (“opposition”) as it being the closest. Which day is it?
Daryl,
Good question! Thanks for giving us the opportunity to clear up any confusion. Yes, Mars comes closest to Earth on the night of December 18-19, 2007. Mars is at opposition on December 24, 2007, at which time the red planet is marginally farther away.
If Earth and Mars revolved around the sun in perfect circles and on the same exact plane, Mars would always be closest to Earth right at opposition. Because the Earth and Mars have elliptical (oblong) orbits, and revolve around the sun on slightly different planes, Mars is not necessarily at its closest point to Earth on the same day that Mars is at opposition. According to the mathematical wizard Jean Meeus, the time interval between Mars’ least distance from Earth and a Martian opposition can be as large as 8.5 days (1969), or less than 10 minutes (2208).
The next opposition of Mars is on January 29, 2010, but the planet comes closest to Earth 2 days earlier, on January 27, 2010.
Bruce
It’s a common misunderstanding that opposition (the point at which a planet is closest to the sun) is the same as the point at which a planet is closest to the earth.
Another interesting tidbit is that the Earth-Mars distance is currently about 5 light-minutes, allowing near real time control of the Mars Rovers. It must be refreshing for the mission controllers to have such “instantaneous” responses!
Tim,
Good point about Mars’ distance in light-minutes! Late next year – on Dec. 5, 2008 – Mars will be at conjunction, or on the far side of the sun. At that juncture, I believe the red planet will be over 20 light-minutes away.
Bruce
Hi, I might have a dumb question for you all….and excuse me in advance if I word it incorrectly. I am very very new at this.
What type of focal length is needed to view detail on Mars? By detail I mean seeing it through the telescope bigger than a star and being able to see at least it’s surface.
Thank you in advance.
Michelle.
Sorry for the late response. I’ve been sidetracked by the Geminids. A power of 100 to 200 times should be fine for viewing Mars. Divide the focal length of the telescope by the focal length of the eyepiece to determine the power. For instance, take a telescope with a focal length of 2000 mm and an eyepiece of 10 mm. 2000 divided by 10 = 200 power. Click here and scroll downward for more information on Mars and the telescope.
Bruce
Hi I have a really good question for you I live in the Alantic Time Zone and that is what time would be the best to see the red planet
thanks Erica Gavel
PS(I love Earth and Sky)
what is your name my name is karem