On 8 May 2022, Astronomy Picture of the Day post this beautiful image from NASA/ESA/Hubble of spiral galaxy NGC 1512 in the far southern skies. The small bright blue central band is called a nuclear ring. Two distinct darker brown spiral arms are gas and dust falling inward from the larger ring at the edges of the image. This in-falling material results in much new star formation yielding the bright blue cast. There are also many areas of new star formation seen in blue scattered around the larger ring.
The powerful NASA launch vehicle SLS carried the Artemis I mission one step closer to its goal of sending astronauts to the Moon and ultimately Mars. The payload of Orion is unmanned on this initial mission profile. It will go to the Moon and 26 days later be back to Earth.
The GOES-16 weather satellite currently in geostationary orbit frequently images the east coast in many wavelengths. It captured the launch seen here in this video clip.
Browsing the Hubble Legacy Archive, the Great Barred Spiral got my attention. I downloaded three greyscale images filtered in blue, green, and red wavelengths which I combined into this color version with software. The result didn’t appear to me as a large spiral galaxy. Spiral arms were present around a bright core of stars. But, it seemed to be missing some larger dimensions than this image showed.
Hubble Legacy Archive | NGC 1365 | Color composite Jim RuebushContinue reading →
It was election day in the U.S. I was up early to go serve as a poll watcher at my local voting place. Because of the lunar eclipse, I was up to view it before leaving the house. The Moon was low in the northwest beginning to encounter some tree branches.
In this first photo, the time was 5:26 am still during the totality phase. A dark tree branch in the foreground can be seen running vertically. I opened a living room window for the image using my digital camera on full zoom. Not quite in focus.
5:26 am | Canon PowerShot SX60 HS | ISO 1600 | 0.6s
I waited awhile for it to emerge from totality at 5:46 am. By then, it had moved farther down into the tree branches to see from the living room. I took the camera and tripod out to the driveway and got a clear view some 3 minutes later.
5:49 am | Canon PowerShot SX60 HS | ISO 1600 | 0.20s
What is MMOD? It is the acronym for Micro-Meteoroid and Orbital Debris. Space debris is a risk to other spacecraft both manned and unmanned. It includes derelict craft, fragments from their disintegration and collision, paint flecks, frozen liquids expelled from spacecraft, and unburned particles from solid rocket motors. The debris comes in a wide range of sizes from microscopic to bigger than a car. Most of it is small. There are estimated more than 128 million pieces of debris smaller than 1 cm (0.4 in), about 900,000 pieces of debris 1–10 cm, and around 34,000 of pieces larger than 10 cm (3.9 in) were estimated to be in orbit around the Earth.
The smallest size of debris like paint flecks and rocket exhaust particles are grouped with the small micrometeoroids from space in a group called MMOD. They pose a definite risk. Collisions with debris cause damage similar to sandblasting on spacecraft surfaces, to solar panels, and to optics like telescopes or star trackers. These small fast particles can puncture thin metals. Collision speed between 10 – 14 km/s (6 – 8.4 mi/s) are likely.
Several years ago I was evaluating science lessons for students who were preparing to take exams. One of these lessons from NASA posed some questions about the number of MMOD impacts felt by the Hubble Space Telescope. During the 2009 STS-125 Shuttle mission, the astronauts removed the Wide- field Planetary Camera 2 (WFPC2) and replaced it with the Wide Field Camera 3 (WFC3). Protecting the WFPC2 while it was aboard Hubble was a curved rectangular aluminum plate covered with white paint. A number of blemishes were observed from a distance on the painted surface and photographed with a telephoto lens from the Shuttle window. They are circled in this image. They were impacts from MMOD recorded during its 16 year exposure in space. More impacts were present but were too small to see from a distance.
How I See It 