Mars – rises as expected in the east but slowly. Despite the 30-hour orbit of Deimos, 2.7 days elapse between its rise and set for an equatorial observer, as it slowly falls behind the rotation of Mars. Because the orbit of Phobos is below synchronous altitude, the tidal forces from the planet Mars are gradually lowering its orbit. In about 50 million years, it could either crash into Mars's surface or break up into a ring structure around the planet. The origin of the two moons is not well understood. Their low albedo and carbonaceous chondrite composition have been regarded as
Two Is Better Than One the top 40. It is also the group's biggest hit to date. By December 2011, "Two Is Better Than One" had sold 1,508,000 copies in the U.S. alone, outselling even other big Taylor Swift hits such as "Tim McGraw" and "Fifteen". As of November 2017, the song has sold 1.7 million copies in the United States. With both related artists receiving acclaim, the song became Boys Like Girls' second consecutive top 40 single on the "Billboard" Hot 100. Also, it gave Swift her twenty-first top 40 song on that chart. For the week of January 9, 2010, the song became