As captured this year from the surface of Mars, the eclipses of Phobos (L) and Deimos (R) can cause… [+] spectacular annular solar eclipses, but not total.
NASA / JPL-Caltech / MSSS / Kevin M. Gill
In our Solar System, any planet with moons has the possibility of a solar eclipse.
Solar eclipses are possible on Earth, and occur every time the Moon is aligned with the Earth-Sun plane.… [+] during a new moon. This same principle applies to any planet with a moon.
flickr user Kevin Gill
They occur every time a moon passes directly between its parent planet and the Sun.
An illustration of the Sun-Moon-Earth configuration that establishes a total solar eclipse. When the… [+] The shadow of the Moon falls on the Earth when the node closest to the Sun is aligned, we obtain a solar eclipse: total if the shadow of the Moon falls on the Earth, cancel if the shadow ends before reaching Earth and partial if the alignment is too imperfect.
STARRY NIGHT EDUCATION SOFTWARE
From planet Earth, they can appear partial, total or annular.
From Earth, eclipses can be partial, annular or total, due to the large angular size of our Moon.… [+] seen from the surface of the Earth. From Mars, its two moons are too small to create total solar eclipses.
But on Mars, only partial or annular eclipses occur.
The closest and largest of Mars’ moons, Phobos, creates a completely alien view during the sun… [+] Eclipses Annual eclipses occur frequently on Mars, even appearing perfectly aligned at times with the Curiosity Rover.
NASA / JPL-Caltech / Malin Space Science Systems / Texas A&M Univ.
Mars has two moons: Phobos and Deimos.
The two moons of Mars, Phobos and Deimos, are small and in relatively close orbits around Mars,… [+] but neither has an angular diameter large enough to be seen from the Martian surface to cause a total eclipse.
NASA / JPL-Caltech
Both are too small to completely cover the Sun’s disk.
As seen from the Martian surface, Phobos (left) and Deimos (right) can block only part of the… [+] Sun; Mars does not experience total solar eclipses.
NASA / JPL / Malin Space Science Systems
Like Earth’s moon, Phobos and Deimos cast cone-shaped shadows as they orbit through the Solar System.
Within the threshold cone, with the vertex to the left of Phobos, the Sun is completely obscured. Within… [+] penumbral cone, with the apex to the right of Phobos, the Sun is only partially obscured. Since the threshold cone does not currently reach the surface of Mars, all eclipses are partial.
Bruce G. Bills and Robert L. Comstock
However, those cones come to an end before finding the surface of Mars.
Although it can never completely block the Sun’s disk, Phobos, the moon of Mars, can project a dark spot… [+] on the surface of the red planet: its shadow penumbral. Observers within that shadow can see a partial or annular eclipse.
NASA / JPL / Malin Space Science Systems
As a result, the solar eclipses of Mars never completely block the Sun’s disk.
The smallest Martian moon, Deimos, has features like craters, composition, and orbital properties.… [+] That puts it in line with a chemical origin similar to Mars itself, rather than a captured asteroid.
NASA / JPL / University of Arizona
Smaller and more distant, Deimos appears small and dark, slowly passing between the Sun and Mars.
This enhanced color image of the Martian moon Phobos shows its irregular and fascinating shape.… [+] surface characteristics. Phobos, while orbiting Mars, creates spectacular annular eclipse views.
NASA / JPL-Caltech / University of Arizona
However, Phobos is larger, closer and more irregular, creating a spectacular silhouette against the sun.
The moon of Mars, Phobos, when passing in front of the Sun on April 4, 2020, was captured by Curiosity.… [+] Rover Mastcam. Its irregular shape can be clearly seen.
NASA / JPL-Caltech / MSSS / Kevin M. Gill
From NASA’s Mars Curiosity Rover Mastcam, humanity learns exactly what Martian solar eclipses are like.
The smallest and most distant moon on Mars, Deimos, looks like just a dot against the bright orb of the Sun.… [+] during an annular eclipse. Still, these are frequent and varied enough that the Curiosity rover has had this type of perfect lineup on numerous occasions.
NASA / JPL-Caltech / MSSS / Kevin M. Gill
Kevin Gill used that data to build real-time eclipse videos for both Martian moons.
The Phobos eclipse occurred on April 4, 2020; Deimos occurred on March 28, 2020.
In its ancient past, Mars may have had a third innermost moon, bringing with it total eclipses.
Instead of the two moons we see today, a collision followed by an circumplary disk may have… [+] spawned three moons from Mars, where only two survive today. Just as Earth’s moon was formed by a large impact a long time ago, so were the moons of Mars.
Labex UnivEarths / Université Paris Diderot
Mostly Mute Monday tells an astronomical story in pictures, images and no more than 200 words. Talk less; smile more.
