I slept under the stars this weekend in southern Utah. The Milky Way was clearly visible. Orion rose late, and the Big Dipper also wasn’t in full view until the middle of the night. I tweeted about my star watching night and @KimberlyKellar of Alaska tweeted back a link to this video. Wow! Enjoy.
After you click on the Play button, click on the four arrows in the lower-right of the Vimeo window to expand.
Tempest Milky Way from Randy Halverson on Vimeo.
For billions of years the Earth has been pelted by bits and pieces of space rocks from the asteroid belt. Yesterday a NASA spaceship arrived at Vesta to explore the second largest asteroid.
This is historic stuff!
One of the first images from our close encounter with Vesta, via NASA:
Caption also from NASA: Asteroid 4 Vesta from Dawn on July 17, 2011. The image was taken from a distance of 9,500 miles (15,000 km) away from Vesta.
Liftoff!
Early morning, May 16, 2011.
The crew of STS-134 this morning en route to the launch pad in NASA's Airstream aka the Astrovan.
Lightning illuminates the launch pad on April 28, 2011, on the eve of the first launch attempt.
NASA’s Dawn mission is closing in on Vesta after a billion-mile journey from Earth. Vesta is the second largest object in the asteroid belt (after Ceres).
This makes 2011 an exciting year for lovers of rocks from space. When we arrive at Vesta, it will be the first time that a spaceship has traveled to the asteroid belt, and orbited a body in the belt.
All asteroids, including what we now call protoplanets, are believed to have formed in the first years of the life of our solar system. After their formation, they have not changed much–as a result they’re the only known surviving pieces of those days over 4.5 billion years ago.
Dawn will arrive at Vesta this July and will orbit it for a year before departing for Ceres. From Earth observations we already know a fair amount about Vesta, however, the data from Dawn will greatly advance our knowledge and understanding of this asteroid aka protoplanet.
The spacecraft carries cameras and spectrometers which will allow us to examine Vesta, map it, and determine in far greater detail its chemical composition.
HED meteorites come from Vesta. These are a subgroup of achondrites. HED stands for “Howardite-Eucrite-Diogenite.” There are different types of meteorites from Vesta because Vesta itself shows much evidence of geologic activity resulting in differentiation of its rocks.
NASA rendition of Dawn analyzing Vesta. This will be actually happening in just a few months.
Today is the 50th anniversary of the first American in space, Alan Shepard! On May 5, 1961, Shepard piloted the Freedom 7 mission.
NASA selected the Mercury 7 astronauts out of 110 of the country’s best pilots. When it came time to assign the first mission, the choice was reportedly fairly easy to make–Shepard stood out among the 7 initial astronauts making him the best of the best.
Shepard was an extraordinary man. If you haven’t watched it yet, I recommend When We Left Earth, a six-part documentary from the Discovery Channel. The first episode gives you some insight into Shepard and you get a glimpse of him in action in the early 1960s. It’s currently available via streaming on Netflix.
Thank you Alan Shepard for bravely going where no American had gone before.
Ceres, the largest asteroid and the first to be discovered (1801) is the only spherical asteroid. All other asteroids have irregular shapes since they lack the necessary gravity to become a sphere. Image from NASA's Hubble Telescope.
One of my favorite Dave Matthews songs is called, “The Space Between.” It’s a song about love, not outer space, but it contemplates that indefinable “space between” two things.
In the space between Mars and Jupiter is the asteroid belt which is the source of over 99% of meteorites. Though it contains many tens of thousands of asteroids, the asteroids in the belt belt have a low combined mass–only 1/30th or 3 to 4 percent of the mass of our moon. As a result, even though there are many thousands of asteroids, the asteroid belt also contains massive gaps.
To understand how wide-open the gaps are in the belt, consider that the chances of a spacecraft colliding with an asteroid while traveling through it have been calculated at one in a billion. Another fact that helps put asteroids into perspective is that it takes them between three and six Earth years to orbit the sun, depending on their distance from the sun. That’s a big orbit path!
Among the many asteroids, in the space between Mars and Jupiter, we find not only the source of meteorites, but the home to the oldest rocks in our solar system.
From NASATV:
NASA photo.
In May of 2008 I had the great honor of watching Mark Kelly and his crew launch space shuttle Discovery. It was a thrill of a lifetime–and surprisingly emotional to see the shuttle take off.
As too many people have come to know (for all of the wrong reasons) Mark is an extraordinary guy. He’s very grounded and has a regular guy demeanor that deflects attention from his exceptional character as well as the fact that he’s a highly skilled astronaut and pilot.
I am also a Wikipedia nerd and I wrote Mark’s bio on Wikipedia. It was recently ranked a “Good Article” something that only 3/10 of 1% of the articles on Wikipedia have achieved.
Read more about Mark on Wikipedia.
Godspeed Mark and crew as you prepare for Endeavour’s final mission. We’re proud of all of you!
“We’re all space dust.” So says my friend with his PhD in physics from the University of Virginia. He’s entirely unimpressed by meteorites. He sees just more space dust, no different from the matter that makes up his own body.
Well, that’s true in a very literal and unimaginative sense.
But meteorites, rocks from space, and mammals, really couldn’t be any more different. If they’re both space dust, one is the least evolved form of dust, whereas the other is the most evolved.
Meteorites, the least evolved matter in our solar system, matter that in some cases formed in the earliest days of our solar system over 4.5 billion years ago, are storied chunks of space dust. They not only tell us about those important formative days of our corner of the Universe, they also had a direct impact on the evolution of life on Earth.
The most recent of mass extinctions was most likely caused by the Earth’s massive collision with a meteoroid at today’s Yucatán Peninsula. This is known as the Chicxulub Impact. It is also likely, but even more difficult to prove because our dynamic Earth has hidden the evidence, that previous mass extinctions are attributable to massive meteoroids hitting our planet.
That event at the Yucatan 65 million years ago set the stage for the evolution of mammals, including humans.
On this Earth Day as many of us think about the impact our species is having on the planet, it’s important to remember the Earth changing impacts of the past. If pieces of a meteoroid survive their collision with our planet we call them meteorites.
For so many reasons, meteorites are more than mere space dust just as we humans are as well.
Rendering of an impact event, from NASA.
