I recently watched a show about alien planets orbiting distant stars. It emphasized the differences between these planets and Earth – too hot, too cold, iron rain, noxious gas – places where humans couldn’t live, but maybe some organisms might.
What I, and everyone else, would like to find is a planet that is like Earth. Some planet orbiting an Earth-like star in the Goldilocks zone – not too hot, not too cold, but just right. A planet with water, and with a breathable atmosphere.
People sometimes think the space between stars is 'empty' but that's not the case. That area is filled with patches of low-density gas and when a relatively dense clump of gas gets near a star, the resulting flow produces a drag force on any orbiting dust particles. The force only affects the smallest particles -- those about one micrometer across, or about the size of particles in smoke.
This explains the otherwise difficult to understand shapes of those dust-filled disks, according to a team led by John Debes at NASA's Goddard Space Flight Center in Greenbelt, Md.
This video, apparently slated to be the first in a series, provides an accessible and visually compelling entry level discussion of the big bang. Hard to imagine that this was done for approximately one infinitieth of the budget of Avatar.
A team of researchers say long held beliefs about how stars are formed have been just a myth, and they say this astronomy myth got busted using a set of galaxies found with CSIRO's Parkes radio telescope.
When interstellar gas collapses to form stars, the stars range from massive to minute. Since the 1950s many astronomers have believed that in a family of new-born stars the ratio of massive stars to lighter ones was always about the same — for every star 20 times more massive than the Sun or larger, you'd get 500 stars the mass of the Sun or less.
The question came up during a lunch today with two NASA computing people, on in IT and the other in supercomputing. Modern satellites are returning petabytes of data, and there are many satellites. This is far more than any human can expect to personally look at, and in fact more than they can fit into their local machine. How do we make these huge amounts of data useful?
We can't ship it to the user's desktop-- there's no room, it'd take forever, and the user doesn't have tools that can browse massive data sets.
My kids asked me if there was enough water in the universe to quench the Sun. I voted yes, but of course science isn't about voting, but about verifiable facts. So now the explanation.
The Sun has a mass of around a third of a million Earths. Stealing a figure from MadSci.org, the mass of water on the Earth is 1/4400 the total mass. We'll say we need enough water to completely douse every atom in that fusion-burning puppy we call Sol, so we'll need... 4400 * 0.3 * a million Earths.
This works out neatly to just over a billion Earths, to get enough water to douse the Sun.
The Big Bang is believed to have created a flood of gravitational waves that still fill the universe with information about its existence immediately after the Big Bang. These waves would be observed as the "stochastic background," analogous to a superposition of many waves of different sizes and directions on the surface of a pond. The amplitude of this background is directly related to the parameters that govern the behavior of the universe during the first minute after the Big Bang.
RCW 38 is a dense star cluster about 5500 light years away in the direction of the constellation Vela (the Sails). Like the Orion Nebula Cluster, RCW 38 is an embedded cluster, in that clouds of dust and gas still envelop its stars.
Inside RCW 38, young stars bombard fledgling suns and planets with powerful winds and blazing light and some short-lived, massive stars explode as supernovae, whick sometimes cooks away the matter that would otherwise form new solar systems.
Did our own solar system form in that sort of hellish environment?