An Ancient Crater Bigger Than Chicxulub

A meteor impact greater than the one that killed the dinosaurs? That's the word from Antactica, where scientists working in the Wilkes Land region have found a crater twice the size of the Chicxulub crater in the Yucatan, which was likely the blow that led to the dinosaurs' demise some 65 million years ago. "This Wilkes Land impact is much bigger than the impact that killed the dinosaurs, and probably would have caused catastrophic damage at the time," said Ralph von Frese, a professor of geological sciences at Ohio State University. Finding such a crater beneath the frozen wastes of Antartica isn't an easy proposition, but tapping the GRACE satellites made the difference. GRACE stands for Gravity Recovery and Climate Experiment; it's a duo of satellites sent into orbit in March of 2002, each flying about 220 kilometers apart in a polar orbit 500 kilometers high. The GRACE experiment maps Earth's gravity by taking measurements of the distance between the satellites using GPS and...

read more

Galactic Collisions and their Aftermath

Einstein's theory of general relativity predicts the existence of gravitational waves, and if it's good enough for Einstein, it's good enough for LISA, the Laser Interferometer Space Antenna mission scheduled for launch in 2015. LISA will search the universe for gravitational waves, a coup if detected since they have until now remained in the domain of theory. And if the spacecraft finds its target, chances are it will be picking up gravitational waves from the collision of supermassive black holes that occur when galaxies merge. All of which is germane to new work by a team led by Stelios Kazantzidis (University of Chicago). Kazantzidis is working on galaxy collisions, simulating them to identify what leads to the mergers of such black holes. After all, if supermassive black hole collisions are numerous, the chances of LISA detecting their gravitational waves go up. The team is using supercomputers to simulate an intricate gravitational dance. Most stars in such galaxy collisions...

read more

Charter

In Centauri Dreams, Paul Gilster looks at peer-reviewed research on deep space exploration, with an eye toward interstellar possibilities. For many years this site coordinated its efforts with the Tau Zero Foundation. It now serves as an independent forum for deep space news and ideas. In the logo above, the leftmost star is Alpha Centauri, a triple system closer than any other star, and a primary target for early interstellar probes. To its right is Beta Centauri (not a part of the Alpha Centauri system), with Beta, Gamma, Delta and Epsilon Crucis, stars in the Southern Cross, visible at the far right (image courtesy of Marco Lorenzi).

Now Reading

Recent Posts

On Comments

If you'd like to submit a comment for possible publication on Centauri Dreams, I will be glad to consider it. The primary criterion is that comments contribute meaningfully to the debate. Among other criteria for selection: Comments must be on topic, directly related to the post in question, must use appropriate language, and must not be abusive to others. Civility counts. In addition, a valid email address is required for a comment to be considered. Centauri Dreams is emphatically not a soapbox for political or religious views submitted by individuals or organizations. A long form of the policy can be viewed on the Administrative page. The short form is this: If your comment is not on topic and respectful to others, I'm probably not going to run it.

Follow with RSS or E-Mail

RSS
Follow by Email

Follow by E-Mail

Get new posts by email:

Advanced Propulsion Research

Beginning and End

Archives