Archive
08/03/2020 – Ephemeris – What is the Perseverance Rover going to do on Mars?
This is Ephemeris for Monday, August 3rd. Today the Sun will be up for 14 hours and 33 minutes, setting at 9:05, and it will rise tomorrow at 6:33. The Moon, at full today, will rise at 9:35 this evening.
The Mars Perseverance Rover looks a lot like the Curiosity Rover that landed on Mars in Gale Crater almost exactly 8 years ago (Earth years that is). It has more and better cameras, some different tools on its arm. It will have a laser like Curiosity. It can take core samples and store them in sealed tubes for later return to the Earth. It has an experimental helicopter drone named Ingenuity that must, like the rover be autonomous since it cannot be controlled in real-time from the Earth. The main mission this time is to look for signs of life in a spot we know water had flowed in the ancient past. The surface water and the life is long gone, but there might be signs that it might have been present in the distant past before Mars lost most of its atmosphere and water.
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.
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.
02/17/2020 – Ephemeris Extra – The Moon will cover the planet Mars in morning twilight tomorrow, Tuesday the 18th.
Sorry, I missed this until now. Tomorrow morning the 18th Mars will be occulted by the Moon. For Northern Lower Michigan Mars will disappear shortly after 7:10 a.m. The exact time depends on your location, so I can’t be more specific. At that time the Moon and Mars will be in the southeastern sky. Mars is now first magnitude, but will fare poorly in the morning twilight, so I’d suggest finding the Moon and Mars at least 15 minutes earlier with binoculars or telescope. Mars will reappear at the Moon’s unlit side around 8:37 a.m. This is after sunrise, so a telescope will be required to spot it. Hoping for clear skies, though the weather forecast isn’t promising.
A map of where the occultation of Mars will be visible. Created using Occult4.
Where Mars will disappear at the Moon’s sunlit edge. Created using Stellarium.
Mars will reappear at the Moon’s unlit edge around 8:36 a.m. give or take. Created using Stellarium.
06-18-2019 – Ephemeris – Mercury and Mars will be seen together tonight
Ephemeris for Tuesday, June 18th. Today the Sun will be up for 15 hours and 34 minutes, setting at 9:31, and it will rise tomorrow at 5:56. The Moon, 1 day past full, will rise at 10:49 this evening.
This evening the Planets Mercury and Mars will appear less than a moon-width apart in the evening twilight. Mercury, the brighter of the two, by a factor of 4 times, will be visible first, at about 10:15 p.m. very low in the west-northwest. Mars will be immediately below it by less than the width of the Moon. At that time they will be a bit less than the width of your fist held at arm’s length above the horizon. Binoculars are the best way to spot them. Mercury will continue to move eastward in the sky away from Mars. Until after it reaches its greatest separation from the Sun on the 23rd. It will then head back and pass at a much greater distance below Mars on July 5th. This is the best chance to spot Mercury in the evening sky this year.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Mercury and Mars this evening at 10:30 p.m., June 18, 2019. Created using Stellarium.
11/26/2018 – Ephemeris – NASA’s InSight spacecraft lands on Mars this afternoon
Ephemeris for Monday, November 26th. The Sun will rise at 7:54. It’ll be up for 9 hours and 11 minutes, setting at 5:05. The Moon, half way from full to last quarter, will rise at 8:43 this evening.
This afternoon NASA’s InSight spacecraft will land on Mars. It will drill into the martial soil to place a temperature probe to measure Mars’ heat flow to determine the interior temperature of Mars. It will also deploy a seismometer to detect marsquakes and seismic waves generated by meteorite impacts to ascertain the interior structure of the planet. The entry, decent and landing or EDL as it’s called begins at 2:47 p.m. Eastern Standard Time, with landing 6 minutes, 45 seconds later. The Jet Propulsion Laboratory calls it Seven Minutes of Terror. The spacecraft is on its own so everything has to go right. Mars is 8 light minutes away. The spacecraft will be on the ground one way or the other for over a minute by the time we get word that the spacecraft has entered the atmosphere of Mars. NASA-TV, available on the Internet, starts its coverage at 2 p.m. Eastern Standard Time.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
To see Emily’s post with a lot more information, click on this URL: http://www.planetary.org/blogs/emily-lakdawalla/2018/mars-insight-landing-preview.html. The post has a link to NASA’s 68 page pdf Mars InSight Landing Press Kit, which covers all aspects of entry, descent and landing, the Mars Insight components, and science instruments, and what they expect to learn about Mars’ interior.
08/02/2018 – Ephemeris – Has liquid water been found on Mars?
Ephemeris for Thursday, August 2nd. The Sun rises at 6:30. It’ll be up for 14 hours and 37 minutes, setting at 9:07. The Moon, 2 days before last quarter, will rise at 12:09 tomorrow morning.
The European Space Agency has announced the possible discovery of liquid water beneath Mars’ southern polar cap. Perhaps it’s like the lakes found under Earth’s Antarctic ice sheet. The discovery was made by the Mars Express orbiter’s ground penetrating radar. Mars south polar cap is primarily made of water ice up to 3.7 kilometers thick, covered in winter by a meter, give or take, thickness of carbon dioxide ice, what we call dry ice. Mars elliptical orbit happens to make southern hemisphere summers short and hot, and winters long and especially cold. Liquid water could exist several kilometers below the martian surface. Mars’ internal heat flow is what NASA’s InSight lander, now en route to Mars is going to tell us.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Mars Express detects water buried under the south pole of Mars. Click on the image to enlarge. Credit: European Space Agency (ESA)
07/30/2018 – Ephemeris – Early tomorrow morning Mars will be the closest to is in 15 years
Ephemeris for Monday, July 30th. The Sun rises at 6:26. It’ll be up for 14 hours and 44 minutes, setting at 9:10. The Moon, 3 days past full, will rise at 10:51 this evening.
Mars’ closest approach to the Earth since August 27, 2003 is tomorrow at about 3:51 a.m. at a distance of 35.8 million miles (57.6 million km). The last really close approach of Mars was on August 27, 2003 when it was about 600 thousand miles (a million km) closer. That close approach was probably the closest in 50 thousand years. Mars and the Earth get close in their orbits about every 26 months. But because Mars has a much more elliptical orbit than the Earth, the very best close encounters occur every 15 or 17 years. Despite the fact that we have satellites that orbit Mars and two rovers operating on its surface, amateur astronomers still challenge themselves to observe and photograph Mars at its very closest.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Mars’ closest approaches to the Earth in the period 2003 to 2018 also showing the apparent sizes of the planet at each approach. Click on image to enlarge. Created using my LookingUp program and Cartes du Ciel (Sky Charts).
07/27/2018 – Ephemeris – Mars is at opposition from the Sun today
Ephemeris for Friday, July 27th. The Sun rises at 6:23. It’ll be up for 14 hours and 50 minutes, setting at 9:14. The Moon, at full today, will rise at 9:16 this evening.
The planet Mars was at opposition with the Sun early this morning, that is opposite the Sun in the sky. It is a time when a planet rises at sunset and sets at sunrise. For us it will rise tonight at 9:40 p.m. 26 minutes after sunset and will set tomorrow at 6 a.m., 24 minutes before sunrise. This odd behavior is due to the fact that Mars is actually south of a lime from the Sun through the Earth. Mars’ orbit is tilted to the Earths’ so it will appear lower in the sky as one would expect for a planet in its position. Today Mars is 35.9 million miles (57.7 million km) away. In four days it will be a bit closer to us due to its elliptical orbit taking it a bit closer to the Sun. How much closer? About 93,000 miles (150,000 km) to us.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
This chart is shown with the horizontal being parallel to the ecliptic, which is the horizontal line near the top of the image. Created using Cartes du Ciel (Sky Charts).
Created using Cartes du Ciel (Sky Charts).
Mars on opposition day, July 27, 2018 at 1:55 a.m. as it crossed the meridian due south. In the Interlochen/Traverse City area a bit south of 45 degrees north latitude. Mars appears a an altitude of slightly less than 20 degrees altitude. Created using Stellarium.
Update
Mars at opposition and the full Moon at 2:01 a.m. July 27, 2018. I thought I’d go out near the Mars transit time this morning and photograph the Moon and Mars. Earlier we had a pop-up rain shower, and the clouds were clearing out. Got a lucky shot.
