Category Archives: Cool Stuff

Dark Matter Hairs Around Earth?


Is Earth surrounded by filaments of dark matter?  It just might. I know, sounds hard to believe to me too.  Not doubting it though, need to keep an open mind about such things. I have a  lot of unanswered questions, I need to read that study.

Take a look at the zoomed-out version linked below too.

JPL explains:

This illustration shows Earth surrounded by filaments of dark matter called “hairs,” which are proposed in a study in the Astrophysical Journal by Gary Prézeau of NASA’s Jet Propulsion Laboratory, Pasadena, California.

A hair is created when a stream of dark matter particles goes through the planet. According to simulations, the hair is densest at a point called the “root.” When particles of a dark matter stream pass through the core of Earth, they form a hair whose root has a particle density about a billion times greater than average.

The hairs in this illustration are not to scale. Simulations show that the roots of such hairs can be 600,000 miles (1 million kilometers) from Earth, while Earth’s radius is only about 4,000 miles (6,400 kilometers).

A zoomed-out version of this concept is at PIA20176.

The California Institute of Technology manages JPL for NASA.

Image Credit: NASA/JPL-Caltech


Phobos Breaking Apart?


Credits: NASA/JPL-Caltech/University of Arizona

I’ve always wondered about the grooves on Phobos.   I always figured they were somehow related to a huge impact.  i never saw one this coming:

The long, shallow grooves lining the surface of Phobos are likely early signs of the structural failure that will ultimately destroy this moon of Mars.

Orbiting a mere 3,700 miles (6,000 kilometers) above the surface of Mars, Phobos is closer to its planet than any other moon in the solar system. Mars’ gravity is drawing in Phobos, the larger of its two moons, by about 6.6 feet (2 meters) every hundred years. Scientists expect the moon to be pulled apart in 30 to 50 million years.

We think that Phobos has already started to fail, and the first sign of this failure is the production of these grooves,” said Terry Hurford of NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

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Lunar Pox


Great title from ESA for this image of the Lunar north pole from the SMART-1 spacecraft.  It’s been a long time since I posted a SMART-1 image!

ESA’s description (included below) talks a lot about the lighting.  The pattern of the craters sort of looks like a spiral to me and that might be the lighting too.

Image: ESA/SPACE-X (Space Exploration Institute). Acknowledgments: J. Manuel Fonseca, M. Costa & A. Mora (UNINOVA); B. Grieger & M. Almeida (ESA)


ESA’s caption:The pockmarked landscape captured in this image from ESA’s SMART-1 mission is the surface of our Moon. Some of the many craters scattered across the lunar surface are clearly visible, records of the many impacts that have plagued it.

At the very centre of this image is the lunar north pole, captured in detail during ESA’s mission. The image shows the characteristic craters of the Moon, present in all shapes and sizes. The largest in view is Rozhdestvenskiy, sandwiched between Hermite to the northeast and Plaskett to the southwest.

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DSA-1 in 3D


Grab those 3D glasses and have a look at this picture from ESA of the Deep Space Network Antenna (DSA 1) with credit to  D. O’Donnell/ESA – CC BY-SA 3.0.

ESA has a large version of this image, see it here.

A visit to DSN Now is a good way to find out which spacecraft are communicating.

From ESA

This 3D anaglyph image, taken on 3 August 2015, shows ESA’s 35 m-diameter deep-space tracking dish at New Norcia, Western Australia, at night. It can be viewed using stereoscopic glasses with red–blue filters.

This Deep Space Antenna, DSA-1, regularly communicates with distant spacecraft such as Mars Express, Rosetta and Gaia. In the near future, it will also work with BepiColombo at Mercury, LISA Pathfinder and ExoMars.

In 2014, it beamed commands and received data from Rosetta, voyaging 800 million km away. On 12 November 2014, it received data relayed by Rosetta as DLR’s Philae craft landed on its target comet.

Despite the moveable structure weighing 580 tonnes, engineers can point it accurately at 1 degree per second in the horizontal and vertical axes.

On 3 August, the dish was illuminated for that evening’s photography – it usually operates in the dark to reduce power usage and avoid light pollution.

In 2015, ESA’s Estrack ground station network celebrates 40 years of European tracking


Exploring the Galactic Center

The center of our Milky Way galaxy is a mysterious place. Not only is it thousands of light-years away, it’s also cloaked in so much dust that most stars within are rendered invisible. Harvard researchers are proposing a new way to clear the fog and spot stars hiding there. They suggest looking for radio waves coming from supersonic stars.

“There’s a lot we don’t know about the galactic center, and a lot we want to learn,” says lead author Idan Ginsburg of the Harvard-Smithsonian Center for Astrophysics (CfA). “Using this technique, we think we can find stars that no one has seen before.”

The long path from the center of our galaxy to Earth is so choked with dust that out of every trillion photons of visible light coming our way, only one photon will reach our telescopes. Radio waves, from a different part of the electromagnetic spectrum, have lower energies and longer wavelengths. They can pass through the dust unimpeded.

On their own, stars aren’t bright enough in the radio for us to detect them at such distances. However, if a star is traveling through gas faster than the speed of sound, the situation changes. Material blowing off of the star as a stellar wind can plow into the interstellar gases and create a shock wave. And through a process called synchrotron radiation, electrons accelerated by that shock wave produce radio emission that we could potentially detect.

“In a sense, we’re looking for the cosmic equivalent of a sonic boom from an airplane,” explains Ginsburg.

To create a shock wave, the star would have to be moving at a speed of thousands of miles per second. This is possible in the galactic center since the stars there are influenced by the strong gravity of a supermassive black hole. When an orbiting star reaches its closest approach to the black hole, it can easily acquire the required speed.

The researchers suggest looking for this effect from one already known star called S2. This star, which is hot and bright enough to be seen in the infrared despite all the dust, will make its closest approach to the Galactic center in late 2017 or early 2018. When it does, radio astronomers can target it to look for radio emission from its shock wave.

“S2 will be our litmus test. If it’s seen in the radio, then potentially we can use this method to find smaller and fainter stars – stars that can’t be seen any other way,” says co-author Avi Loeb of the CfA.

This work is reported in a paper authored by Idan Ginsburg, Xiawei Wang, Avi Loeb, and Ofer Cohen (CfA). It has been accepted for publication in the Monthly Notices of the Royal Astronomical Society.

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.

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