Monday, December 7, 2015
Going where no other spacecraft has gone before, New Horizons has sent back some pretty stunning images of Pluto--from endearing heart-shaped features to giant ice mountains. And the images just keep getting better.On Friday, NASA released the first batch of the sharpest-ever images of the former planet. The view above shows the region where the flat Sputnik Planum meets the al-Idrisi mountains. It has a resolution of 250-280 miles per pixel, "revealing features less than half the size of a city block!
The new details revealed here, particularly the crumpled ridges in the rubbly material surrounding several of the mountains, reinforce our earlier impression that the mountains are huge ice blocks that have been jostled and tumbled and somehow transported to their present locations
More stuff ! Yes More!
The Japan Aerospace Exploration Agency's Akatsuki probe fired its small attitude-control thrusters for 20 minutes Sunday evening in a second and final attempt to enter Venus orbit. Akatsuki's first try — which came exactly five years earlier, on Dec. 6, 2010 — failed when the probe's main engine conked out during the orbit-insertion burn, sending the spacecraft sailing off into deep space.
It's too early to know if Akatsuki is indeed circling the second planet from the sun, the spacecraft's handlers said.
"The orbiter is now in good shape," Japan Aerospace Exploration Agency (JAXA) officials wrote in a mission update Sunday. "We are currently measuring and calculating its orbit after the operation. It will take a few days to estimate the orbit; thus we will announce the operation result once it is determined."
The $300 million Akatsuki mission, whose name means "Dawn" in Japanese, launched in May 2010 to study the clouds, weather and atmosphere of Venus, with the aim of helping scientists understand how the planet ended up so much hotter and less life-friendly than Earth. (Surface temperatures on Venus are hot enough to melt lead.)
Sunday, December 6, 2015
This tiny ball provides evidence that the universe will expand forever. Measuring slightly over one tenth of a millimeter, the ball moves toward a smooth plate in response to energy fluctuations in the vacuum of empty space. The attraction is known as the Casimir Effect, named for its discoverer, who, 55 years ago, was trying to understand why fluids like mayonnaise move so slowly. Today, evidence indicates that most of the energy density in the universe is in an unknown form dubbed dark energy. The form and genesis of dark energy is almost completely unknown, but postulated as related to vacuum fluctuations similar to the Casimir Effect but generated somehow by space itself. This vast and mysterious dark energy appears to gravitationally repel all matter and hence will likely cause the universe to expand forever. Understanding vacuum energy is on the forefront of research not only to better understand our universe but also for stopping micro-mechanical machine parts from sticking together.