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04/25/2023 – Ephemeris – The Moon is passing Mars today
This is Bob Moler with Ephemeris for Tuesday, April 25th. Today the Sun will be up for 13 hours and 57 minutes, setting at 8:40, and it will rise tomorrow at 6:40. The Moon, 2 days before first quarter, will set at 2:50 tomorrow morning.
Tonight, the Moon and the planet Mars will appear close to each other. The Red Planet will appear just below and left of the waxing crescent Moon. Mars is a lot dimmer than it was last December. That’s because it is a lot farther away than it was back then, 157 versus 51 million miles (253 versus 82 million kilometers). Mars is the planet with the greatest distance variation percentage over its synodic period, that is, from opposition to the next opposition. It also has the longest synodic period, at 26 months on average. That’s why opportunities to launch spacecraft only occur every 26 months. The least energy it takes to get to Mars occurs when a spacecraft is launched a few months before opposition, when Mars is at its closest, to arrive several months after opposition.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –4 hours). They may be different for your location.
Addendum
The Moon and Mars as they should appear in the west tonight, April 25, 2023, at 10 pm. Created using Stellarium.
Illustration of the route Mars 2020 (Perseverance) took to arrive at the Red Planet, including several trajectory correction maneuvers (TCMs) to adjust its flight path. Credit NASA/JPL.
01/21/2021 -Ephemeris – The Perseverance rover is less than a month from landing on Mars
This is Ephemeris for Thursday, January 21st. Today the Sun will be up for 9 hours and 24 minutes, setting at 5:36, and it will rise tomorrow at 8:11. The Moon, 1 day past first quarter, will set at 2:40 tomorrow morning.
The Mars Perseverance Rover is approaching the Red Planet. In a bit less than a month, on February 18th it will plunge into the martian atmosphere to land near an ancient river delta in the 28 mile (45 kilometer) wide crater Jezero. The dramatic entry-descent-and-landing or EDL is what the Jet Propulsion Laboratory, that built and manages the rover, calls Seven Minutes of Terror due to the complexity of the landing process and the fact that they will be bystanders at that point. By the time they receive confirmation that the encapsulated rover has hit the top of the martian atmosphere it would have already landed, or crashed on the martian surface. It will take over 11 minutes for signals to reach us from Mars that day.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Delta of ancient river that flowed into a lake in the Jezero crater. This is a false color imaging highlighting mineral types. Credit NASA.
Mars Perseverance Rover’s planned landing ellipse partially overlapping the dried up river delta. Credit: NASA/JPL.
Mars 2020 Rover “Perseverance” destined for the martian crater Jezero.
Bob Moler's Ephemeris Blog 