NASA’s Mars Perseverance rover has filmed the Martian satellite (or moon) Phobos eclipsing the sun, and this short but impressive video may be viewed online.^1,2 During the eclipse, Phobos passes in front of the solar disk, covering part of it. Does this eclipse have relevance to the subject of origins?

Yes! Although this eclipse was impressive, it is a reminder that, within our solar system, “perfect” solar eclipses occur only here on Earth. The sun is 400 times larger than the moon, but the moon is 400 times closer to the earth than the sun. Therefore, despite the large differences in their sizes, both the moon and sun have the same apparent size when we see them in the sky. For this reason, during a perfect solar eclipse, the moon just barely, but perfectly, covers the disk of the sun. In our solar system, such perfect eclipses occur only on Earth, and Earth is the only planet in our solar system that has beings (namely, us) capable of appreciating such events. And such perfect eclipses have served as treasure troves of scientific information. Is this an amazing coincidence, or an indication of design?³

Also, creation researchers have noted that Phobos’ decaying orbit could be an indication of youth.^4,5 Phobos is slowly spiraling inward toward Mars at about 1.8 centimeters per year.⁶ Similar to the slow outward recession of our own moon away from the earth,⁷ Phobos’ slow inward spiral is caused by gravitational “tidal forces” between it and Mars.⁸

If the time for a satellite (or moon) to orbit its planet is less than the planet’s rotation period, the satellite will spiral inward. If, on the other hand, the time for a satellite to orbit its planet is greater than the planet’s rotation period, the satellite will spiral outward. Phobos’ orbital period (about 8 hours) is less than Mars’ rotation period (about 25 hours), so Phobos is spiraling inward toward Mars, as noted earlier.

For how long has Phobos’ orbit been decaying? Left to itself, a satellite spiraling inward toward a planet will continue its inward spiral: its inward motion will not stop or reverse. Likewise, a satellite receding away from a planet will, if left to itself, continue to do so: its outward motion will not stop or reverse.

This means the maximum possible time that Phobos’ orbit could have been decaying is the time it took for its orbital period to decrease from 25 hours to 8 hours.⁹ Had Phobos’ orbital period ever been greater than 25 hours, it would have started moving away from Mars, not toward it. And left to itself, that outward motion would never cease or reverse. That Phobos is moving toward (not away from) Mars means that Phobos’ orbital period was never more than 25 hours.¹⁰

How long would it take for Phobos’ orbit to decrease from 25 hours to 8 hours? We don’t know exactly, but it is probably measured in millions of years, not billions. Phobos is thought to only have 50 million years left before it is destroyed.⁶ Hence, its past history is also likely measured in millions of years, at most. Hence, Phobos must be relatively young. By the same reasoning, Mars’ other satellite, Deimos, must also be fairly young.

Mainstream astronomers recognize this and have proposed (relatively) recent origin scenarios for these two Martian satellites. But such ideas have problems.^4,5 The most popular idea is that Phobos and Deimos are asteroids captured by Mars’ gravity. But Phobos and Mars have very circular orbits, which are not expected to result from such a scenario.^4,5 Likewise, such a “capture” scenario needs a thick Martian atmosphere in order to slow down the captured satellites, but Mars’ atmosphere is quite thin.⁴ Even former NASA Chief Historian Steven J. Dick has acknowledged that “the capture mechanism is unknown and the scenarios unlikely.”^4,11

Phobos and Deimos may be two more indications of recent creation,^12,13 with maximum possible ages of millions of years, despite the fact that conventional astronomers believe the solar system to be billions of years old. And because these are maximum possible ages, their true ages could be just 6,000 years, consistent with the Bible’s history. So enjoy the eclipse video from the Martian surface, and remember that the Lord Jesus Christ deserves the glory for His recent creation of our solar system.

References 
1. NASA’s Perseverance rover captures video of solar eclipse on Mars. Phys.org. Posted on phys.org April 20, 2022, accessed April 21, 2022. 
2. The 43 second video may be viewed here. 
3. Gonzalez, G. and J. W. Richards. 2004. The Privileged Planet. Washington, DC, Regnery: 1-19.
4. Catchpoole, D. 2018. Mars moons mystery: How did Phobos and Deimos get to where they are? Creation. 40 (3): 50-51.
5. Faulkner, D. 2019. An Evaluation of Astronomical Young-Age Determination Methods I: the Solar System. Answers Research Journal. 12: 255-274. 
6. Tillman, N. T. Phobos: Facts About the Doomed Martian Moon. Space.com. Posted on space.com December 7, 2017, accessed April 22, 2022. 
7. Hebert, J. Lunar Recession in the News. Creation Science Update. Posted on ICR.org June 25, 2020, accessed April 22, 2022.
8. Tidal forces are forces caused by a difference in the strength of the force of gravity on one side of a body compared to the other side.
9. Of course, over millions of years, tidal recession could cause Mars’ orbital period to change as well, but here we ignore that complication for ease of explanation. Also, the masses of Phobos and Deimos are negligible compared to that of Mars, so such a change would probably not be very large.
10. This of course, assumes that Phobos has been “left to itself” throughout its history, but this is precisely the assumption that uniformitarians make, since they claim that “all things continue as they were from the beginning of creation” (2 Peter 3:4).
11. Steven J. Dick. Under the Moons of Mars. NASA. Posted on nasa.gov November 19, 2007, accessed April 22, 2022. 
12. Hebert, J. 2018. Our Young Solar System. Acts & Facts. 47 (9). 
13. Recently, researchers suggested a couple of other possible scenarios for the formation of Phobos and Deimos. Creationists should probably examine these newer scenarios in more detail before we can make a strong claim regarding the age of these Martian moons.

Stage Image: Mars rover Perseverance
Stage Image credit: Copyright © NASA. 2022. Adapted for use in accordance with federal copyright (fair use doctrine) law. Usage by ICR does not imply endorsement of copyright holder.

*Dr. Hebert is Research Scientist at the Institute for Creation Research and earned his Ph.D. in physics from the University of Texas at Dallas.