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02/25/2021 – Ephemeris – Moon Dust, bad stuff

February 25, 2021 Leave a comment

This is Ephemeris for Thursday, February 25th. Today the Sun will be up for 10 hours and 58 minutes, setting at 6:25, and it will rise tomorrow at 7:24. The Moon, 2 days before full, will set at 7:30 tomorrow morning.

One of the big problems that will have to be solved before the Artemis program sets up a permanent base on the Moon is what to do about lunar soil or Moon dust. That stuff gets into everything. The Apollo astronauts said it smelled like gunpowder. Unlike beach sand the particles aren’t rounded, but angular, being produced by rocks being hit by meteoroids large and micro over the eons by space weathering. With no atmosphere small particles can even weld themselves together. Though no studies have been done, any brought into the habitat would do damage to the lungs, like that to miners on Earth. Moon dust has compromised the seals on the containers of soil the Apollo crews brought back from the Moon.

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

Addendum

Lunar soil

Lunar soil sample. Credit Larry Taylor U of TN Knoxville from https://ntrs.nasa.gov/api/citations/20090026015/downloads/20090026015.pdf

02/23/2021 – Ephemeris – The Perseverance rover landed on Mars taking video all the way down

February 23, 2021 Leave a comment

Note: There was a news conference at JPL, Monday at 2 pm EST where videos of the parts of the landing were shown. Most hadn’t made it to the https://mars.nasa.gov website by Monday night. The news conference with the videos can be found on NASA TV, NASA’s YouTube channel and other sites.

This is Ephemeris for Tuesday, February 23rd. Today the Sun will be up for 10 hours and 52 minutes, setting at 6:22, and it will rise tomorrow at 7:28. The Moon, halfway from first quarter to full, will set at 6:15 tomorrow morning.

It looks like the Perseverance Rover was gently lowered to a flat spot in Jezero crater on Mars about a kilometer or two from the edge of the river delta it was aiming to be near. It is in the midst of checkouts and the unfolding of its masts and its various appendages. For the third time the Mars Reconnaissance Orbiter was able to take a picture of the entry craft on its parachute seen above the delta, as it had with Curiosity and the Phoenix lander before all the while performing its communication relay duties. A few images have come back from Percy, as the Rover is nicknamed as I record this Sunday night. By Monday Percy should have sent back more images and perhaps parts of the landing video.

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

Addendum

Looking down at Perseverance from the Sky Crane

A frame from the video looking down at the Perseverance rover from the Sky Crane. In the video as the rover neared the ground it was enveloped by a cloud of dust, so the support lines simply disappeared into the cloud of dust that enveloped the rover. Click on the image to enlarge. Credit NASA/JPL.

Perseverance rover on the parachute from MRO

The Perseverance rover on the parachute over Jezero crater from the Mars Reconnaissance Orbiter. The circle on the image is the point where the rover landed. Click on the image to enlarge. Credit NASA/JPL-Caltech/University of Arizona.

02/22/2021 – Ephemeris – What’s happening with NASA’s Artemis Moon Program

February 22, 2021 Comments off

This is Ephemeris for Monday, February 22nd. Today the Sun will be up for 10 hours and 49 minutes, setting at 6:21, and it will rise tomorrow at 7:30. The Moon, 3 days past first quarter, will set at 5:28 tomorrow morning.

It appears that the Artemis Moon Program is still on schedule despite a new administration and a setback when a few weeks ago an all up 8 minute firing of the 4 main engines of the Space Launch System Core Stage aborted after little over a minute. (NASA is scheduled to repeat this Green Run test this week) The first launch of the complete rocket is slated for later this year with an uncrewed lunar orbit mission. Recently NASA announced that Elon Musk’s SpaceX was awarded the contract to launch the first two lunar gateway modules on a single Falcon Heavy rocket. The two modules, Power and Propulsion Element (PPE) and Habitation and Logistics Outpost (HALO) will be placed in low earth orbit. From there the PPE would use its ion engines to propel the two modules out to a near rectilinear halo orbit of the Moon over many months.

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

Addendum

SLS first green run at Stennis

SLS first green run of all 4 RS-25 engines mounted on the core stage for the Artemis-1 mission on a test stand at Stennis Space Center in Mississippi. Credit: NASA.

Lunar Gateway PPE and HALO modules

An artist’s depiction of the Lunar Gateway PPE and HALO modules in lunar orbit. The PPE module is the part with the solar panels. Credit: NASA.

 

02/18/2021 – Ephemeris – The Perseverance Rover will land on Mars this afternoon

February 18, 2021 Comments off

This is Ephemeris for Thursday, February 18th. Today the Sun will be up for 10 hours and 37 minutes, setting at 6:15, and it will rise tomorrow at 7:36. The Moon, 1 day before first quarter, will set at 1:30 tomorrow morning.

Later this afternoon the Perseverance Rover will land in Jezero crater on Mars. NASA will have a live Internet feed from the Jet Propulsion Laboratory starting at 2:15 pm EST (19:15 UTC). Atmospheric entry will be at 3:48 pm EST (20:48 UTC), landing at 3:55 pm EST (20:55 UTC). This is Earth received time. The events actually happened 11 minutes 22 seconds earlier on Mars. Though cameras on the spacecraft will be recording the landing activity it will not be sent to Earth in real time due to the weak signal during entry. The spacecraft will be sending tones only for specific events during what is called EDL, Entry, Descent and Landing or “Seven Minutes of Terror”. If all goes well the first images will be taken and sent of its surroundings. And in the next weeks we’ll get an actual replay sent back of the landing with color and sound. It will be so cool!

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

Addendum

Links

NASA on YouTube: https://www.youtube.com/results?search_query=nasa

NASA TV: https://www.nasa.gov/multimedia/nasatv/#public

Entry, Descent and Landing

Graphic of the Entry, Descent and Landing of the Perseverance Rover. Click on the image to enlarge. Credit: NASA/JPL.

Perseverance drilling for sample

Perseverance drilling for a sample in Jezero crater. Artist drawing – NASA/JPL

02/16/2021 – Ephemeris – Perseverance lands on Mars in two days

February 16, 2021 Comments off

This is Ephemeris for Fat Tuesday, Tuesday, February 16th. Today the Sun will be up for 10 hours and 32 minutes, setting at 6:13, and it will rise tomorrow at 7:39. The Moon, 3 days before first quarter, will set at 11:24 this evening.

In two days, Thursday afternoon, the Perseverance Rover will land on the planet Mars in a crater call Jezero. It’s mission to actually look for evidence of past life, fill specimen tubes to be cached for later pickup and returned to earth by a future mission, presumably by the end of the decade. It is also bringing a helicopter drone named Ingenuity to check out the feasibility of using future aircraft in Mars rarefied atmosphere. The vehicle, including the back shell and descent stage sports 23 cameras. Even Ingenuity has 2 cameras. That shouldn’t be a big deal today. Heck, my smartphone has 5 cameras, each with lots more megapixels than the digital camera I bought 15 years ago. Only two days to go to landing.

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

Addendum

Entry, Descent and Landing

Graphic of the Entry, Descent and Landing (EDL) of the Perseverance Rover. Click on the image to enlarge. Credit: NASA/JPL.

Link to the Mars 2020 Perseverance Landing Press Kit

01/21/2021 -Ephemeris – The Perseverance rover is less than a month from landing on Mars

January 21, 2021 Comments off

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

Ancient delta flowing into

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 Endurance Rover's planned landing ellipse

Mars Perseverance Rover’s planned landing ellipse partially overlapping the dried up river delta. Credit: NASA/JPL.

Mars 2020 Rover "Endurance"

Mars 2020 Rover “Perseverance” destined for the martian crater Jezero.

11/05/2020 – Ephemeris – Water found on the daylit side of the Moon

November 5, 2020 Comments off

This is Ephemeris for Thursday, November 5th. Today the Sun will be up for 9 hours and 58 minutes, setting at 5:25, and it will rise tomorrow at 7:28. The Moon, 3 days before last quarter, will rise at 8:55 this evening.

Last week NASA announced some results from their SOFIA airborne observatory. They had detected the spectral signature of water in a large crater on the Moon named Clavius. This was a high latitude crater, 58.6 degrees south. Supposedly one could process a cubic meter of the regolith to extract a half liter of water. Clavius, which science fiction fans will note was the location of the American base on the Moon in 2001 a Space Odyssey. It is also one of my favorite lunar craters, one of the largest with a distinctive arc of diminishingly sized craters in its floor. As far as resources go, we’ve just literally scratched the surface of the Moon in its equatorial regions with our Apollo and other country’s robotic missions.

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

Addendum

Moon with Clavius circled

The Moon as seen from Australia (south up) with the crater Clavius circled. This is the same view of the Moon that users of a Newtonian reflector telescope in the northern hemisphere see, and how I first explored the Moon with my reflecting telescope. Source abc.net.au.

Closeup of Clavius

Closeup of Clavius from the Lunar Reconnaissance Orbiter. Credit: NASA/LRO.

Sophia Airborne Observatory

The SOFIA Airborne Observatory. A modified Boeing 747 with a 106 inch (2.7 meter) telescope mounted crosswise in its fuselage. It is a joint project between NASA and the German Aerospace Center (DLR) and for some reason always on the verge of being canceled. Credit: NASA.

SOFIA is of course an acronym for Stratospheric Observatory for Infrared Astronomy. For more on SOFIA click here: https://www.nasa.gov/mission_pages/SOFIA/index.html.

10/29/2020 – Ephemeris – A look at Bennu the asteroid

October 29, 2020 Comments off

This is Ephemeris for Thursday, October 29th. Today the Sun will be up for 10 hours and 17 minutes, setting at 6:34, and it will rise tomorrow at 8:18. The Moon, 2 days before full, will set at 7:06 tomorrow morning.

Tonight we will have Mars appearing above the bright gibbous Moon in the evening sky. Out in space NASA’s OSIRIS-REx spacecraft is still in the vicinity of the tiny asteroid Bennu. The asteroid is about 60 percent the distance between the Earth’s and Mars’ orbits, but on the far side of the Sun from us. This is why it will take 3 years to return the sample to the Earth. Bennu is small, only 743 feet (226.5 meters) in diameter. And is a rubble pile asteroid with lots of empty voids between the rocks. The sampler instead of stopping at the surface, punched into the asteroid surface a bit. Bennu was picked because is a potential hazardous asteroid and is a particularly primitive type of asteroid.

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

Addendum

Bennu and Earth showing distance

Inner Solar when OSIRIS REx took its sample from Bennu. Bennu’s official designation is 101955 Bennu. The number designation is the consecutive number it is given when placed on the official list of asteroids and dwarf planets when its orbit is determined. Notice that it was on the other side of the Sun. Credit NASA’s Eyes app.

The asteroid Bennu is 743 feet (226.5 meters) in diameter. It is a carbonaceous asteroid. OSIRIS-REX has already discovered water bearing clays on its surface. Credit NASA

10/27/2020 – Ephemeris – NASA’s cup runneth over with asteroid bits

October 27, 2020 Comments off

This is Ephemeris for Tuesday, October 27th. Today the Sun will be up for 10 hours and 23 minutes, setting at 6:37, and it will rise tomorrow at 8:16. The Moon, half way from first quarter to full, will set at 5:04 tomorrow morning.

One week ago the NASA’s OSIRIS Rex spacecraft unfolded its sampling arm, and folded up it solar panels so as to look like a one legged stork landing and touched a small level patch of small jagged rocks on the tiny asteroid Bennu. A nitrogen bottle was triggered to blow soil and small rocks into a cylindrical container which created quite a blizzard of small rocks. A flap on the collection device was supposed to close, keeping the collected bits in, but was propped open by a large rock, so some of the contents started to leak out. Now flight controllers must gently maneuver the collector into the return canister without losing too much of the contents. The sample canister is expected to return to Earth in 2023.

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

Addendum

Artist depiction OSIRIS-REx TAG (Touch and Go)

Artist depiction OSIRIS-REx TAG (Touch and Go) from video. Credit NASA.

Animated GIF of the actual sample collection

Animated GIF of the actual sample collection TAG (Touch and Go). Credit NASA.

For more information go to https://www.nasa.gov/osiris-rex

 

10/23/2020 – Ephemeris – What is a Near Rectilinear Halo Orbit?

October 23, 2020 Comments off

This is Ephemeris for Friday, October 23rd. Today the Sun will be up for 10 hours and 34 minutes, setting at 6:44, and it will rise tomorrow at 8:10. The Moon, at first quarter today, will set at 12:46 tomorrow morning.

When the astronauts of the Artemis program head for a landing on the Moon is as little as four years from now they will meet their lunar landing craft or Lunar Gateway space station with landing craft docked to it before they descend to the Moon. The orbit of the gateway and/or lander is an odd one. It’s called a near rectilinear halo orbit. And uses the motion and gravitational interaction of the Moon and Earth to create an orbit of the Moon which is nearly face-on to the Earth. The vehicles will never pass behind the Moon. The orbit will pass 1,900 miles (3,000 km) above the Moon’s north pole and out to 43,000 miles (70,000 km) above the south pole. It’s called a halo orbit, because as seen from the Earth it appears to trace a halo around the Moon.

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

Addendum

NASA CAPSTONE pathfinder for gateway orbit

NASA CAPSTONE* pathfinder for gateway orbit is to be launched next year by Rocket Lab to prove out the near rectilinear orbit for the Lunar Gateway. The orbit will always be more or less face on to the Earth, so it and the lunar lander will be always be in contact with the Earth. Credit Advanced Space via Spaceflight Now.

* Yes, CAPSTONE is an acronym: Cislunarˆ Autonomous Positioning System Technology Operations and Navigation Experiment. Aren’t you glad you asked?

ˆ Cislunar: The volume of space between the Earth and Moon’s orbit.

Lunar Gateway NASA

An artist’s rendition of the Lunar Gateway with the Orion spacecraft docked to it. Credit NASA.

For more information

https://spaceflightnow.com/2019/09/26/nasa-to-fly-cubesat-pathfinder-for-gateway-in-unique-lunar-orbit/

https://www.space.com/nasa-capstone-cubesat-moon-gateway.html