New Delhi: NASA’s Perseverance rover has captured another solar transit from Mars, with the moon Phobos crossing the Sun. Perseverance has previously captured such solar transits on Mars in February this year and in April 2022. Phobos is the larger of the two moons of Mars, and is a odd, potato-shaped lump, and has not managed to assume a spherical shape under the influence of its own gravity. The Perseverance Rover captured the solar transit from its perch on the western wall of the Jezero Crater, the region that it is exploring. The ground teams had to carefully orchestrate the operations of the camera on the mast of the rover to capture the transit.
The solar transit was captured on 30 September. Phobos obscured a large portion of the Sun’s disc, while its shadow moved across the surface of the planet. Phobos is about 27 kilometres wide, and is 157 times smaller than the Moon. The transit was rapid because the orbit of Phobos is almost perfectly aligned to the Martian equator. The moon also is in a close orbit around the planet, taking only 7.6 hours for a lap. A transit lasts for only about 30 seconds. Such events are not considered eclipses as the full disc of the Sun is not covered by the Moon.
Fear and Dread
Such observations help scientists refine the orbit of the moon, and better understand how the orbit is evolving. Phobos is slowly spiraling into Mars, with its altitude constantly reducing. Scientists estimate that Phobos will crash into Mars in about 50 million years. The origins of the Martian moons are a contentious subject, with some scientists suggesting they are primordial remnants from the infancy of the Solar System, while others believing them to be captured asteroids. Phobos was discovered in 1877 by the American Astronomer Aseph Hall, along with Deimos, the smaller moon of Mars. The two moons are named after the Greek deities of Fear and Dread.
