Archive for May 8, 2020

05/08/2020 – Ephemeris – A look at Mars 2020 Endurance Rover’s target crater: Jezero

May 8, 2020 Comments off

This is Ephemeris for Friday, May 8th. Today the Sun will be up for 14 hours and 34 minutes, setting at 8:56, and it will rise tomorrow at 6:21. The Moon, 1 day past full, will rise at 10:43 this evening.

The Mars 2020 Rover will be launched on July 17th or thereabouts to land at the crater Jezero* on the Red Planet. What’s the big deal about Jezero? In very early Martian history the crater was filled with water with a river flowing into it. What’s left is a dry river delta. The landing ellipse target for the rover will land it near the leading edge of that delta. Spectral analysis from the Mars Reconnaissance Orbiter has detected clays that can contain, on Earth, fossils of single celled organisms. The rover is not equipped with a powerful enough microscope to detect them so they will be cached to be returned to the Earth sometime in the future as one of its objectives. Scientists believe that Mars was friendly for life for only a billion years or so.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.


Jezero is pronounced like the biblical character Jezebel.

Jezero Crater

Jezero Crater on a map by the Mars Orbiter Laser Altimeter (MOLA) instrument on the Mars Global Surveyor spacecraft (1996-2006). Colors code by altitude (blue-low to red-high). Click on the image to enlarge. Credit NASA/JPL.

Jezero Crater

The Jezero crater from the European Space Agency’s Mars Express Orbiter. Jezero is 30.4 miles (49.0 km) in diameter. Note the river delta on the left (west) forming a lake with an outlet on the right. Click on the image to enlarge. Credit: NASA/JPL/MSSS/ESA.

Mars Endurance Rover's planned landing ellipse

Mars Endurance Rover’s planned landing ellipse partially overlapping the dried up river delta. Click on the image to enlarge. Credit: NASA/JPL.

Ancient delta flowing into

Delta of ancient river that flowed into a lake in the Jezero crater. Color coded based on minerals present. Click on the image to enlarge. Credit NASA.