Perseverance Rover

Much of the excitement has settled now that Mars 2020 Perseverance Rover is safely on the surface of Mars after the 18 Feb 2021 landing. I gathered images and links to a collection of things I feel tell the story of this rover in a not too complicated way. The mission is very challenging. A primary goal is to find evidence that microbial life may have existed on the Martian surface in the past.

Perseverance is undergoing system checks for the many sophisticated tools it carries while imaging the surroundings. Scientists are eager to begin moving the rover across the ground and to test the helicopter Ingenuity it carried under the chassis.

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Touchdown in Jezero Crater

You might wonder where Perseverance landed and why is that place is important. Landing took place in Jezero Crater. The crater is about 49 km (30 mi) across. It is believed to have once been filled with water. This image shows a dried riverbed and delta of a water source that once flowed left-to-right and filled the crater. The colors are indicators of various types of mineral deposits and not actual colors. The rover landed in the lower right quadrant of this image just below the two side-by-side small craters on the flat plain and not far from the delta formation.

Ancient river delta into Jezero Crater | MRO | NASA

NASA Perseverance Mars Rover

Scientists and space enthusiasts are excited about the upcoming landing of the exploration rover Perseverance on the surface of Mars on 18 Feb 2021. The NASA-TV broadcast from Mission Control starts at 11:15 am PST/2:15 pm EST.

The mission is designed to look for bio-signatures in a river delta of an ancient lakebed. It will harvest rock-core samples for analysis and possible return to Earth in a future mission. The rover will be joined by a small helicopter to extend its vision and reach around the area. This video (< 3 min) shows the basics of the rover design and plans for the mission. You are invited to explore more about the mission at this link.

Perseverance helicopter being examined by NASA engineers

Perseverance was launched in July of 2020. It took 7 months to coast to this meeting with Mars. On a collision course, it will enter the thin atmosphere at over 12,000 mph. The challenge is how to safely slow the vehicle and land it. This following graphic illustrates the overall plan, but not to scale.

The fast-moving craft in coast phase enters the atmosphere at upper left. A heat shield protects it and slows it down from 12,000 to 950 mph. A parachute deploys and the heat shield falls away. The craft scans the terrain to find the landing site.

At 180 mph and 1.3 miles altitude, the parachute is detached letting the vehicle fall. Rocket engines control the descent and slow it down to less than 2 mph and 60 ft. above the surface. The rover is lowered about 20 ft more by cables to touchdown on the surface. The cables detach and the rocket assembly flies far out of the way.

NASA

Lowering of rover by cables for touchdown | NASA

The technique has been done before in 2012 when the Curiosity rover landed on Mars. It was described then as 7 minutes of terror. Mars is far from Earth. By the time radio signals reach us more than 11 minutes later, events will already have played out, successfully or not. All actions are programmed. Curiosity is still functioning well on Mars today. Here is a recent selfie.

Dial-a-Moon | 2021

What will the Moon look like on any date in 2021? What will it look like on your birthday? Find out at NASA Dial-a-Moon. The example pictured below is for 16 January 2021. Set dates and see views for northern hemisphere and for southern hemisphere readers by following either link. Enter any month and day to see a high definition image. You may leave the universal time (UT) at the default value. If you wish, your local-to-Universal time conversion can be done at this link. Or, type ‘universal time’ into Google. Go back to Dial-a-Moon to enter the UT.

After visiting Dial-a-Moon, scan down that web page for a wealth of additional information about the Moon’s motions and appearance. The images of Dial-a-Moon are made from those of the Lunar Reconnaissance Orbiter (LRO) in low altitude orbit around the Moon since 2009.

NEOWISE | Evening and Morning Views

We were finally blessed with clear skies and got our first views of C/2020 F3 (NEOWISE), or Comet NEOWISE. Most sightings by others thus far have been in the early pre-dawn hours. This week, NEOWISE will become a better evening apparition after 9:30 pm.

Last evening on 12 July, we went to our viewing site with a clear view of the northwest horizon. It was predicted to be at a direction of 328˚ and an altitude of 6˚ above the horizon. (West = 270˚, North = 360˚) Your fist at arm’s length is about 10˚ tall. We scanned with binoculars for several minutes as the sky slowly darkened. There it was.

Canon PowerShot SX60 HS | ISO1600 | 1 sec | Full Zoom

Astro-Images | Centaurus-A

Centaurus-A is located in the southern hemisphere skies.  I have never seen it from my location 42˚ north latitude. It rises only 5˚ above my southern horizon in early December. I’m certain it is very familiar to my blogger friend Roger in Australia.  It is the 5th brightest galaxy and easily viewed by amateurs. It contains a black hole of 55 million solar masses ejecting jets of x-ray and radio wavelengths. Models suggest the galaxy collided with another smaller galaxy in the past leading to areas of star formation in the resulting complex structure. I enjoyed combining 3 greyscale Hubble images into this composite. In the center are several newly formed bluish stars. The dark areas are dust blocking the passage of light.

Centaurus-A | Hubble Legacy Archive | My Version