Here is a great video about the newly announced Kepler 452b with SETI scientists: Douglas Caldwell, Jeffrey Coughlin, Joseph Twicken. and hosted by Seth Shostak.
The Hangout fills in a lot of the blanks from the news reports. As I expected we don’t yet have a mass or density on this planet. Once we get at least a good estimate on these numbers for 452b then we will be able to make better guesses on its composition.
We have an estimate of the diameter so that’s a start, but it’s only one bit of the equation that defines the balance the must exist. If for example, 452b has the density of Earth, we might expect an atmosphere to be much different than we have, ranging up to perhaps even Neptune-like. On the other hand the mass could be much less and the weaker gravity could allow more of the lighter gasses to be lost to space.
I am bound to guess we are very close to finding a real Earth analog. It is astounding how quickly the search is progressing.
About the image: An artist’s rendering shows a windbot bobbing through the skies of Jupiter, drawing energy from turbulent winds there. This notional windbot is portrayed as a polyhedron with sections that spin to absorb wind energy and create lift, although other potential configurations are being investigated. Image credit: NASA/JPL-Caltech
On 29 June a “bright event” was seen across several US Southeastern states at 05:29 UTC; in fact there are more than 150 reports probably related to this event. Early data suggests this object was not a meteor. NASA tracked the object with five cameras, the velocity was about 6.48 km/sec / 14,500 mph much too slow to be a meteor.
The image above shows that it broke up and this combined with the slow speed indicates a possible re-entry of some type of space debris.
In a possible related event, earlier in the day at between 00:30 and 01:00 UTC an explosion was heard at my location, not just here but heard for miles. Police were apparently notified of smoke sighted in an area about 5 miles from here. If I can find out where exactly they were sent, I’m grabbing a magnet and going hunting!
The image above via NASA was taken near Rosman, North Carolina.
There has been an ongoing discrepancy involving estimating the age of Saturn. Models that correctly predict Jupiter’s age of 4.5 billion-years-old can only get Saturn’s age to 2.5 billion-years. That’s 2 billion years off (or 2,000 million years if you prefer).
The press release from Sandia Labs is below, any press release mentioning metallic hydrogen at high pressures and helium rain has to be good!
From Sandia Labs: Experiments at Sandia’s Z machine may help solve that problem when they verified an 80-year-old untested proposition that molecular hydrogen, normally an insulator, becomes metallic if squeezed by enough pressure. At that point, a lattice of hydrogen molecules would break up into individual hydrogen atoms, releasing free-floating electrons that could carry a current, physicists Eugene Wigner and Hilliard Huntington predicted in 1935.
“That long-ago prediction would explain Saturn’s temperature because when hydrogen metallizes and mixes with helium in a dense liquid, it can release helium rain,” said Sandia researcher Mike Desjarlais. Helium rain is an energy source that can alter the evolution of a planet.
Following the Dark Matter Lab sim, here’s yet another simulation.
This simulation uses a NASA supercomputer to simulate a planet and debris disk around a neighbor star Beta Pictoris. We see the (exo) planetary motion drives spiral waves throughout the disk and this action increases collisions among the orbiting debris.
Astronomers Erika Nesvold (UMBC) and Marc Kuchner (NASA Goddard) essentially created a virtual Beta Pictoris in the computer and watched it evolve over millions of years. It is the first full 3-D model of a debris disk where scientists can watch the development of asymmetric features formed by planets, like warps and eccentric rings, and also track collisions among the particles at the same time.
From NASA: Jeremy Schnittman, an astrophysicist at NASA’s Goddard Space Flight Center, developed a computer simulation to follow the orbits of hundreds of millions of dark matter particles, as well as the gamma rays produced when they collide, in the vicinity of a black hole. He found that some gamma rays escaped with energies far exceeding what had been previously regarded as theoretical limits.
Population III stars are the hypothetical first stars. These stars are extremely metal poor but massive stars.
By metals we are talking about elements heavier than hydrogen (and helium depending on which definition you read and is what I consider to be a non-metal too). All elements heavier than hydrogen are a by-product or ash from fusion in the cores of stars.
Population II stars have little metals, stars in globular clusters are made up of a good percentage of population 2 stars. Population II stars are considered to have created all other elements in the periodic table beyond hydrogen and helium. Prior to 1978 or 1979 these were the stars thought to be the oldest stars and still are the oldest observed stars.
Population I stars are considered metal rich young stars and include our own Sun and are common in the arms of the Milky Way.
Now astronomers using the W. M. Keck Observatory, ESO’s Very Large Telescope, Subaru Telescope and the Hubble Space Telescope have discovered the brightest galaxy so far and have evidence of first generation stars within.