Tom's Astronomy Blog

Moonrise

Tom — Tue, 21 May 2013 17:52:08 +0000

Moonrise over Earth. Credit: ESA/E. Lakdawalla

I decided I needed to find something sort of quiet to post today considering the tragic events of yesterday and the loss of the kids in Oklahoma. Have heard from my friends in OKC and thankfully they are well. They are not out of the woods yet though as more storms are moving in..

This image is from the ESA website. You can see the moonrise from the ESA Rosetta spacecraft during it’s first flyby and just before its closest approach on March 3, 2005. Along with it being a nice image, this was actually reprocessed from by Emily Lakdawalla who did a masterful job.

The backstory is pretty interesting too, check it out.

The image description from ESA.

Venus Launch

Tom — Mon, 20 May 2013 17:41:29 +0000

This is the first topographical map of Venus and it was made in the Pioneer program.

It was 35 years ago on this day. The Pioneer Venus Orbiter was launched atop an Atlas-Centaur rocket. The launch kicked off the Pioneer project and was one of two components, the second of which launched in August of 1978.

After the May 20, 1978 launch the orbiter arrived at Venus and was placed into orbit on December 4, 1978. The oribiter was 2.5 meters (8.2 feet) across by 1.2 meters (3.49 feet) high and was packed with 17 experiments.

See here for details.

One of the products was the first topographical map of Venus shown at the top of the post.

The Pioneer Venus Orbiter provided data until 1992 when it entered and was destroyed by the atmosphere of Venus. It is worth mentioning that for the first ten years of operation and that includes building the spacecraft, the cost was 125 million dollars.

Pioneer project from Wikipedia
Pioneer project from NASA

Impact!

Tom — Sun, 19 May 2013 16:57:38 +0000

Click here to view the embedded video.

I put up a picture of a relatively new crater on the moon a few days back. Some good questions came up and I thought I’d post a link to a impact simulator and then lo’ and behold this video came up at the same time.

NASA has been watching the moon for the past 8-years, no I don’t mean just casual viewing, but more of a programmatic endeavour. There have been a number of witnessed lunar impacts over the years, the brightest of which was on March 17th of this year. Ten times brighter than anything seen before. interestingly enough there was a plethora of fireballs seen over Canada on that date too so it seems there was a debris stream interacting with the Earth Moon system. Here’s NASA’s Science@NASA story.

The object was only 0.3 to 0.4 meters (yes 1 foot to a bit more than that) traveling about 56,000 mph. The energy released was about the same at 5 tons of TNT. This is NOT that crater from the post by the way.

Also keep in mind for most practical purposes there is no atmosphere on the moon to slow down a moving body before it gets to the surface, i.e. no meteor showers.

One of the questions was how big of a rock would make that crater. One of the questions was how big of a rock would make that crater. Not sure about the moon but there are a few simulators you can put values into to see what would happen here on Earth. My favorite WAS this version of Impact: Earth! Old school you could say still it is very good.

Then I found an updated version of Impact Earth!, very cool! Try them both.

Here’s something to get you going:

Chelyabinsk meteor (estimates)
Velocity: 18.6 km/sec
Size: 17 to 20 meters
Angle: < 20 deg
Composition: Stoney

Video

Radio Jets

Tom — Sat, 18 May 2013 16:43:58 +0000

Jets from a black hole imaged in a collaborative effort. Image Credit: NASA

Did you see this Image of the Day at the NASA site?

This is another of those collaborative efforts in the astronomical community. I think they set a good example.

So the caption that came with the image (below) explains it pretty well. I usually try and sort out what is going on before reading the real story, happy to say I’m getting pretty good at it. LOL.

Oh, you can get different sizes at the NASA IOTD site.

This composite image of a galaxy illustrates how the intense gravity of a supermassive black hole can be tapped to generate immense power. The image contains X-ray data from NASA’s Chandra X-ray Observatory (blue), optical light obtained with the Hubble Space Telescope (gold) and radio waves from the NSF’s Very Large Array (pink).

This multi-wavelength view shows 4C+29.30, a galaxy located some 850 million light years from Earth. The radio emission comes from two jets of particles that are speeding at millions of miles per hour away from a supermassive black hole at the center of the galaxy. The estimated mass of the black hole is about 100 million times the mass of our Sun. The ends of the jets show larger areas of radio emission located outside the galaxy.

Driving Record for NASA

Tom — Fri, 17 May 2013 17:15:56 +0000

On May 15, 2012 the Mars Rover Opportunity set a record. Credit: NASA/JPL-Caltech

The 9-year old Mars Rover Opportunity just set a NASA record. The record is for the total distance for any NASA vehicle driving on a world other than here on Earth.

The Rover Opportunity has driven 35.76 Km so far in the 9 year mission. What’s the record? The record is held by the amazing Russian Lunokhod 2 at just over 37 Km. No, it won’t be long.

Just for fun here is a page with images of Lunokhod 2 and the surrounding area at the LROC site.

The news release from JPL / NASA:

PASADENA, Calif. — While Apollo 17 astronauts Eugene Cernan and Harrison Schmitt visited Earth’s moon for three days in December 1972, they drove their mission’s Lunar Roving Vehicle 19.3 nautical miles (22.210 statute miles or 35.744 kilometers). That was the farthest total distance for any NASA vehicle driving on a world other than Earth until yesterday.

The team operating NASA’s Mars Exploration Rover Opportunity received confirmation in a transmission from Mars today that the rover drove 263 feet (80 meters) on Thursday, bringing Opportunity’s total odometry since landing on Mars in January 2004 to 22.220 statute miles (35.760 kilometers).

Cernan discussed this prospect a few days ago with Opportunity team member Jim Rice of NASA Goddard Space Flight Center, Greenbelt, Md. The Apollo 17 astronaut said, “The record we established with a roving vehicle was made to be broken, and I’m excited and proud to be able to pass the torch to Opportunity.”

The international record for driving distance on another world is still held by the Soviet Union’s remote-controlled Lunokhod 2 rover, which traveled 23 miles (37 kilometers) on the surface of Earth’s moon in 1973.

Opportunity began a multi-week trek this week from an area where it has been working since mid-2011, the “Cape York” segment of the rim of Endeavour Crater, to an area about 1.4 miles (2.2 kilometers) away, “Solander Point.”

NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover Project for NASA’s Science Mission Directorate, Washington. JPL also manages the Mars Science Laboratory Project and its rover, Curiosity, which landed on Mars in August 2012.

Goodbye Rhea?

Tom — Thu, 16 May 2013 16:48:25 +0000

A nice look at the surface of Rhea, the second largest moon of Saturn. Image: NASA/JPL-Caltech/Space Science Institute

Sorry to see this the last targeted flyby of Rhea. Like it hints at the end. Not going there yet.

This is a remarkable image don’t you think?

NASA’s info on the image:

On its fourth and final targeted flyby of Rhea, the Cassini spacecraft provided this stunning view of the ancient and heavily cratered surface. Billions of years of impacts have sculpted Rhea’s surface into the form we see today.
With a diameter of 949 miles (1,528 kilometers) Rhea is Saturn’s second-largest moon.
This view is centered on terrain at 33 degrees north latitude, 358 degrees west longitude. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on March 9, 2013.
The view was acquired at a distance of approximately 2,280 miles (3,670 kilometers) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 92 degrees. Image scale is 72 feet (22 meters) per pixel.

OR you can visit the Cassini site to see more.

Alien Atmospheres

Tom — Wed, 15 May 2013 17:45:14 +0000

A team of researchers belonging to a group called Project 1640, which is partly funded by NASA’s Jet Propulsion Laboratory, Pasadena, Calif., used the Palomar Observatory near San Diego to obtain detailed spectra of the four planets. The results are revealing new information about the atmospheres of the four giant, red planets.

This image shows the HR 8799 planets with starlight optically suppressed and data processing conducted to remove residual starlight. The star is at the center of the blackened circle in the image. The four spots indicated with the letters b through e are the planets Image and caption courtesy of Project 1640 / NASA

The study of exo-planets, just science fiction not too many years ago is really getting exciting, espeically now that some can be directly imaged and their atmopshere’s are begining to reveal themselves at least in a broad fashion.

Amazing, but I’m still trying to understand the image. As Ben Oppenheimer, lead author of a new study on the subject and the chair of the Astrophysics Department at the American Museum of Natural History in New York said: “”It’s like taking a single picture of the Empire State Building from an airplane that reveals a bump on the sidewalk next to it that is as high as an ant”; so I don’t feel too bad LOL.

Here is a link to the press release, worth the read because it does explain what is going on.

Expedition 35 Returns

Tom — Tue, 14 May 2013 13:21:01 +0000

Click here to view the embedded video.

Being from a helicopter monitoring the Soyuz return, the video is a little shaky.

There is just something about landing on the ground. I know, tried and true but that jolt at the end. Everybody is safe and sound.

Source

Un-named Crater

Tom — Mon, 13 May 2013 17:21:57 +0000

A fresh looking crater with a beautiful eject pattern. Image Credit: NASA/GSFC/Arizona State University

Here is what looks from the bright material to be a fresh crater on the moon, this one isn’t named yet.

According to the LROC team, the dark center in the otherwise bright ejecta is either a different type of material or could be impact melting. The black dots in the ejecta plume could be either again a different material type or they could be from secondary craters.

It is located on the northern part of Mare Fecunditatis. Specifically the location is 3.64°N, 48.93°E. As bright as this crater is it could be tough to spot; it’s small only about 180 meters (590 feet) in diameter. For scale, the image is 930 meters (2962 feet) across.

You can click the image to enlarge it, better yet click here and go to the LROC site to the zoomable version of the crater and surrounding area.

Hawking Radiation

Tom — Sun, 12 May 2013 16:38:19 +0000

Click here to view the embedded video.

A clip from a BBC documentary explaining Hawking radiation around black holes.

Negative mass??

Source