07/30/2020 – Ephemeris – This morning is the first opportunity to launch the Perseverance Rover to Mars

This is Ephemeris for Thursday, July 30th. Today the Sun will be up for 14 hours and 42 minutes, setting at 9:10, and it will rise tomorrow at 6:28. The Moon, 3 days past first quarter, will set at 3:11 tomorrow morning.

This morning is the scheduled launch of the Mars 2020 Rover named Perseverance. The launch will have or had launched at 7:50 am. Or the whole thing was scrubbed for today. I can’t tell, I recorded this last Sunday night. To hit a spot on Mars less than six miles in diameter after a six and a half month coasting flight is quite a fete. Mars is not only moving in orbit of the Sun, but also rotating. The aeroshell the rover is packed in must hit the Mars atmosphere in the right place, and the right time despite the light time from Mars of 11 minutes, 22 seconds. It will take 6 minutes, 50 seconds for the rover to land after it hits the top of Mars’ atmosphere. So it will have landed one way or another before we get the signal that it hit the atmosphere.

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

Addendum

Atlas V with Mars 2020 Rover aboard on launch pad. Click on the image to enlarge. Credit: United Launch Alliance (ULA).

07/28/2020 – Ephemeris – The Mars Endurance Rover may launch to Mars on Thursday

This is Ephemeris for Tuesday, July 28th. Today the Sun will be up for 14 hours and 47 minutes, setting at 9:12, and it will rise tomorrow at 6:26. The Moon, 1 day past first quarter, will set at 1:49 tomorrow morning.

This Thursday at 7:50 am is the first opportunity to launch the Mars 2020 or Perseverance Rover to Mars to arrive on February 18th 2021. The rover will be launched on a United Launch Alliance Atlas 5/Centaur rocket with 4 solid boosters. To send a payload to Mars one must launch within a specific window of time called a launch period. This was originally from July17 to August 11th. Some issues with testing caused a delay to July 30th. The launch period was extended to August 15th. Miss that and it’s a wait of 26 months until Earth and Mars are in the same relative position to try again. The landing area or ellipse is less than 6 miles long on the long axis and partially overlaps an ancient dried river delta that flowed into Jezero crater.

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

Addendum

An artist’s concept of the Mars 2020 Rover launch. The rocket is an Atlas V with 4 solid boosters and a Centaur upper stage. Credit NASA.

 

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

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.

Addendum

Jezero is pronounced like the biblical character Jezebel.

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.

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 partially overlapping the dried up river delta. Click on the image to enlarge. Credit: NASA/JPL.

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.

05/07/2020 – Ephemeris – JPL and NASA preparing a return to Mars via rover and helicopter

This is Ephemeris for Thursday, May 7th. Today the Sun will be up for 14 hours and 32 minutes, setting at 8:55, and it will rise tomorrow at 6:22. The Moon, at full today, will rise at 9:26 this evening.

The Endurance Mars Rover will be launched on or after July 17th. To land on Mars February 18th next year. It has until August 5th to launch. That’s a 20 day launch window. Miss that and it’s a wait of approximately 26 months for the next launch window when the Earth and Mars get into the proper relative positions again. The target of the rover is Jezero crater at the edge of a large Martian feature that can be seen in small telescopes called Syrtis Major. Syrtis Major is cooler sounding than what it means in Latin… The Great Swamp*. Anyway, Jezero crater itself is named after a Bosnian town in 2007 by the International Astronomical Union which named interesting features on Mars after earthly towns. What’s so interesting about Jezero? The answer tomorrow.

* There’s no water there.  It’s actually a volcanic plain, maybe a low shield volcano.

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

Addendum

Artist rendition of the Mars 2020 “Endurance” Rover. Credit NASA.

Artist’s concept of the Mars Helicopter “Ingenuity”. Credit: NASA/JPL-Caltech.

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. I’ll have a closer look tomorrow. Credit NASA/JPL with my labels.