This illustration shows the events that occur in the final minutes of the nearly seven-month journey that NASA’s Perseverance rover takes to Mars. Hundreds of critical events must execute perfectly and exactly on time for the rover to land on Mars safely on Feb. 18, 2021.
Entry, Descent, and Landing, or “EDL,” begins when the spacecraft reaches the top of the Martian atmosphere, traveling nearly 12,500 mph (20,000 kph). It ends about seven minutes later, with Perseverance stationary on the Martian surface. Perseverance handles everything on its own during this process. It takes more than 11 minutes to get a radio signal back from Mars, so by the time the mission team hears that the spacecraft has entered the atmosphere, in reality, the rover is already on the ground.
NASA’s Jet Propulsion Laboratory in Southern California built and will manage operations of the Mars 2020 Perseverance rover for NASA.
The February Membership Meeting of the Cuyahoga Astronomical Association (CAA) will take place Monday, February 8, from 7:30 to 9:00 p.m. via the Zoom online meeting service. The evening’s speaker will be CAA member Dr. Geoffrey Landis who will present, “What is Happening on Mars?”
Dr. Landis is a research scientist for NASA and acclaimed Science Fiction Writer. His specialty has been the various Mars rover missions and he will be showing us what NASA is doing now and in the near future to explore the Red Planet!
Attendees may join the Zoom meeting beginning at 7:20 p.m. the nights of CAA scheduled meetings and meetings begin at 7:30.
The evening will begin with introductions and the featured speaker followed by the monthly membership business meeting, typically concluding at about 9 PM. Guest attendees are welcome.
To attend:
You can either “Phone in” or watch and participate via “Zoom Video”.
Phone In: Just dial: 1-312-626-6799 (Chicago number)
You will be required to enter our meeting number: 954 8268 6049
The first 2021 Membership Meeting of the Cuyahoga Astronomical Association (CAA) will take place Monday, January 11, from 7:30 to 9:00 p.m. via the Zoom online meeting service. The evening’s speaker will be CAA member Matt Franduto who will present, “My 2020 Calendar and the images I took and included or excluded!” Club member Mat Franduto is one of our astrophotographers and every year he produces a calendar based on the astronomical images that he took during the previous year. He will show the pics he included, the ones he excluded, and perhaps a few surprises!
Attendees may join the Zoom meeting beginning at 7:20 p.m. the nights of CAA scheduled meetings and meetings begin at 7:30.
The evening will begin with introductions and the featured speaker followed by the monthly membership business meeting, typically concluding at about 9 PM. Guest attendees are welcome.
On December 21, 2020 Jupiter and Saturn will appear closer in our sky than they have since the year 1623 — only .10º apart. By way of comparison, Earth’s Moon covers about .50º on average! In fact, the two planets will have so little visual separation that they may appear as one bright “star” in our evening sky. As with many objects we see in our night sky, planets Jupiter and Saturn will only appear to be near to each other; they will will be physically separated by about 456 million miles.
The position of the planets as they will be at 7:00 PM EST, December 21, 2020. The bright green line represents the sight line from Earth to Jupiter and Saturn. Image Credit: SkySafari / James Guilford
Here’s why the planets will appear so close in our sky:
Viewed from Earth and looking out toward Jupiter and Saturn we see the planets as if they were in the same orbit — like watching runners in their separate lanes as one overtakes the other. Viewed from “above” we can see that the planets remain well apart.
Viewed closer to the orbital plane of the planets we see how Jupiter and Saturn appear closer together against the background of space. The green line represents the sight line from Earth to the planets. Image Credit: SkySafari / James Guilford
As we drop lower and closer to the orbital plane it becomes more difficult to separate Jupiter and Saturn until, on December 21, 2020, we won’t be able to see them as discrete objects without the use of a telescope!
Jupiter and Saturn appear to merge, on December 21, 2020 as viewed from Earth and depicted here just above the orbital plane of the planets. Image Credit: SkySafari / James Guilford
While the previous extremely close conjunction took place in 1623, Jupiter and Saturn were too close to the Sun to be observed. The last time they could actually be seen so close together was even longer ago: on March 4, 1226. Great Conjunctions take place just short of 20 years apart and most are not so close as this year’s — the next will take place on October 31, 2040, when Jupiter and Saturn will be separated by 1.1º which will be close, but not so amazing as 2020.
Jupiter and Saturn may be seen in the same narrow field of view during 2020’s Great Conjunction. This simulation depicts the position of Jupiter’s Galilean Moons and Saturn’s giant satellite, Titan. Image Credit: SkySafari
If you plan to take a look, you’ll need clear skies (of course!) and you’ll need to be timely — the planetary pair will become visible low in the southwestern sky with the fading twilight and will set in the west by 7:20 PM, December 21. To see the individual planets during their close encounter will require a telescope — a small one will do — or a decent telephoto lens on a camera mounted on a tripod. Given good optics and clear skies, viewers will be able to make out the Galilean Moons of Jupiter and, perhaps spy Titan, Saturn’s brightest moon.
Before and after the 21st, Jupiter and Saturn will appear close together as they first approach, and then recede from the conjunction, continuing to move along their orbital paths. The historic astronomical event will be one night and one night only in our lifetimes. Clear skies, please!
