About 1 billion years after the Big Bang, the gas in deep space was highly opaque to ultraviolet light and its transparency varied widely from place to place, obscuring much of the light emitted by distant galaxies. This opaque quality contains tantalizing mysteries about the universe.
That's because now the gas between galaxies is almost totally transparent thanks to being kept ionized-- electrons detached from their atoms--by an energetic bath of ultraviolet radiation.
I am very happy to host here today an article by my INFN colleague Alessandro de Angelis, a well-known and authoritative italian astrophysicist. Alessandro has recently published a beautiful new book on this subject, which I invite you to have a look at (see link at the bottom of the article) - T.Dorigo .
You may have trouble finding a hotspot in that store you are visiting, but there is one place they are persistent: inside neutron stars. A new study shows that instabilities can create intense magnetic hot spots that survive for millions of years, even after the star's overall magnetic field has decayed significantly.
When a massive star consumes its nuclear fuel and collapses under its own gravity in a supernova explosion, it can result in a neutron star. These very dense objects have a radius of about 10 kilometers and yet are 1.5 times more massive than the Sun. They have very strong magnetic fields and are rapid rotators, with some neutron stars spinning more than 100 times per second round their axis.
Though evidence to-date shows we are the first advanced species, at least in our cosmic neighborhood, that doesn't mean it can't happen elsewhere. It is absolutely likely, because according to one estimate
there are as many as 700 million trillion
terrestrial planets just in the observable universe.
The moon is just a big rock in Earth's orbit now but things could have gone a lot differently in the distant past. In fact, there may have been two early windows of habitability for Luna.In a new paper
, astrobiologists say conditions on the lunar surface were sufficient to support simple lifeforms shortly after the moon formed from a debris disk 4 billion years ago and again during a peak in lunar volcanic activity around 3.5 billion years ago. During both periods, planetary scientists think the moon was spewing out large quantities of superheated volatile gases, including water vapor, from its interior.
With the discovery of a dozen new tiny moons of Jupiter that planet now has upwards of 79 moons. Are all-natural satellites of a planet moons? Not really, not unless they are similar to our Moon in objective physical properties. Many of these moons are like Phobos and Deimos, the moons of Mars, in terms of their gross physical properties. These are bodies which are in fact captured asteroids or very asteroid like. Some formed with Jupiter and orbit in the same direction that it rotates, prograde. Some orbit against the direction of Jupiters orbit retrograde orbit.
The asteroid Oumuamua ("scout from the distant past" in Hawaiian) was discovered on October 19, 2017 by astronomers at thr Pan-STARRS1 survey when it came close to Earth's orbit, within the orbit of Mercury, about a month after its closest approach to the Sun It was called an asteroid - but it may be a comet.
Why the confusion? There are more data about its trajectory. Oumuamua was unlike any asteroid or comet observed before. It sped past the Sun, approaching from "above" the plabe of the planets on a highly inclined orbit, moving fast enough (70,800 miles per hour as of July 1, 2018) to escape the Sun's gravitational pull and eventually depart our Solar System.
A cosmic crash 8 billion to 10 billion years ago was a defining event in the early history of the Milky Way and reshaped the structure of our galaxy.
The Sausage Galaxy lost and the Milky Way won, fashioning both its inner bulge and its outer halo. The wreckage is all around us and the paths of the stars from the galactic merger earned them the moniker "the Gaia Sausage."
By using infrared wavelengths, the HAWK-I infrared imager mounted on ESO's Very Large Telescope (VLT) in Chile was able to capture this image of the star cluster RCW 38.
RCW 38 is over 5,00 light years away (look toward the constellation Vela) and is composed of several short-lived massive stars that will eventually supernovae, but also has some 8,000 other x-ray emitting objects.
Life may be common amongst the stars, but perhaps very far away. But new research published in Nature
hints that it could be much closer than we expected. And it may be on a world of water and ice.
It seems that in a posthumous gift to humanity, the celebrated Cassini spacecraft
may have revealed that Enceladus, one of saturn's great moons, holds the building blocks of life.