Deimos, the smaller of Mars’ two moons, may literally be a chip off the old block.
That’s the conclusion of scientists in the United Arab Emirates, whose Hope orbiter — dubbed the Emirates Mars mission and the country’s first interplanetary spacecraft — just captured the best images of Deimos ever captured by a human spacecraft. .
“We’re getting the highest resolution ever,” said Hessa Al Matroushi, the science leader of the mission at the Mohammed Bin Rashid Space Center in Dubai.
Mars has two irregularly shaped moons and neither is powerful. Phobos, the larger of the two, is about 27 kilometers in diameter at its widest and orbits closer to the red planet at an altitude of about 6,000 kilometers. Deimos is only nine miles wide on its longest side and completes a Mars orbit at an altitude of 24,000 miles every 30 hours.
The small size and idiosyncratic dimensions of the moons led to the suggestion that they could be asteroids captured by Mars long ago. Not so, say researchers analyzing data captured by Hope, which entered orbit around Mars in February 2021.
The mission, primarily intended to study the Martian atmosphere, has spent 2023 in an extended phase performing multiple flybys of Deimos. Hope got as far as 60 miles above the mini-moon’s surface in March, a distance surpassed only by NASA’s Viking 2 orbiter in 1977, which reached about 30 miles above the surface, but with more primitive instruments and cameras.
Hope’s three scientific instruments were able to examine the composition of Deimos. They found that it was more like Mars, namely in the amount of carbon and organic matter present, than like D-type asteroids, the class of asteroids previously suggested as origins. “It looks more like Mars than an asteroid,” said Ms Al Matroushi. However, it is not yet clear how the moon would have formed from Mars.
The spacecraft also obtained the first-ever images of the moon’s far side, which always faces away from Mars, like our moon faces Earth. Differences between the near and far side of Deimos have yet to be analyzed.
Hope will continue its mission in 2024, observing Deimos throughout 2023 in addition to its ongoing Mars observations. Later in the decade, a Japanese mission called Martian Moons eXploration, or MMX, will study the Red Planet’s satellites and attempt to return samples from Phobos to Earth that could pinpoint the moons’ origins.
The next spacecraft the Emirates want to build is a mission to the asteroid belt, launching in 2028. The success of the Hope orbiter may indicate more exciting science to come. “It honestly exceeded our expectations,” said Ms. Al Matroushi.
