Two spacecraft launched for Mars this month: Mars Orbiter Mission on November 5, and MAVEN on November 18. MAVEN is now on an interplanetary trajectory, while Mars Orbiter Mission is still in Earth orbit and will not depart for Mars until the end of the month. A lot of people are asking me: why the difference? Here's your answer, with input from Dave Doody.
It had never occurred to me to think about geostationary satellites in Mars orbit before reading a new paper by Juan Silva and Pilar Romero. The paper shows that it takes a lot more work to maintain a stationary orbit at an arbitrary longitude at Mars than it does at Earth.
Posted by Emily Lakdawalla on 2011/01/04 11:02 CST
While I was writing yesterday's blog entry on Mars Express' Phobos flybys I realized that I didn't understand Mars Express' orbit very well. So I sent an inquiry to the Mars Express blog, which they answered in a blog entry today.
Posted by Emily Lakdawalla on 2010/01/12 11:52 CST
In less than 24 hours, a newly discovered asteroid known as 2010 AL30 will be zipping past Earth at an altitude of approximately a third the Earth-Moon distance. There's no chance it'll hit us, but it's generating a lot of excitement in the community of amateur and professional near-Earth asteroid observers.