Recent revised estimates upping the number of galaxies in the universe seem even more mind-boggling when contemplating this image released from Hubble this week. It shows NGC 362, one of about 150 globular clusters on the outskirts of just one galaxy, our own Milky Way. Read the rest
In the 1990s, Hubble surprised astronomers by revealing just how packed the universe is with galaxies: they estimated some 200 billion of them based on its observations. But now we know these estimates were wrong. There are at least 2 trillion.
Conselice and his team reached this conclusion using deep-space images from Hubble and the already published data from other teams. They painstakingly converted the images into 3-D, in order to make accurate measurements of the number of galaxies at different epochs in the universe's history. In addition, they used new mathematical models, which allowed them to infer the existence of galaxies that the current generation of telescopes cannot observe. This led to the surprising conclusion that in order for the numbers of galaxies we now see and their masses to add up, there must be a further 90 percent of galaxies in the observable universe that are too faint and too far away to be seen with present-day telescopes. These myriad small faint galaxies from the early universe merged over time into the larger galaxies we can now observe.
"It boggles the mind that over 90 percent of the galaxies in the universe have yet to be studied. Who knows what interesting properties we will find when we discover these galaxies with future generations of telescopes? In the near future, the James Webb Space Telescope will be able to study these ultra-faint galaxies, said Conselice.
That's good for about 700 billion trillion stars, and heaven knows how many planets. (Previously) Read the rest
Astronomers working with the NASA Hubble Space Telescope have captured images of what might be water vapor plumes erupting from the surface of Jupiter's moon Europa. “This finding bolsters other Hubble observations suggesting the icy moon erupts with high altitude water vapor plumes,” reports NASA. “ The observation increases the possibility that missions to Europa may be able to sample Europa’s ocean without having to drill through miles of ice.”
Read the rest
Bipolar planetary nebulae occur when a twin star system lies at the center, forming beautiful wing-like symmetrical lobes. The Hubble team estimates this translucent beauty occurred only 1200 years ago. Read the rest
In honor of the Hubble Space Telescope's 25th anniversary, NPR celebrates the iconic space craft with a little help from Iggy Azalea's “Trouble.” Read the rest
From NASA's Image of the Day blog: "This face-on galaxy, lying 45 million light-years away from Earth in the southern constellation of Fornax (The Furnace), is particularly attractive for astronomers. NGC 1097 is a Seyfert galaxy. Lurking at the very center of the galaxy, a supermassive black hole 100 million times the mass of our sun is gradually sucking in the matter around it. The area immediately around the black hole shines powerfully with radiation coming from the material falling in." Read the rest
This is one of the most-famous astronomy photos in the world. Called "The Pillars of Creation" it was taken by the Hubble telescope in 1995 and shows massive columns of hydrogen gas and dust in the Eagle Nebula—7,000 light years from Earth. Part of why these are a big deal is that columns of dust and gas like this are places where stars form.
But here's a cool and/or disappointing detail I hadn't known about until today. Back in 2007, researchers took more images of this region of space using the Spitzer Space Telescope. These shots suggest that the Pillars of Creation might actually be long gone—destroyed thousands of years ago by a nearby supernova.
A striking image from Spitzer shows the intact dust towers next to a giant cloud of hot dust thought to have been scorched by the blast of a star that exploded, or went supernova. Astronomers speculate that the supernova's shock wave could have already reached the dusty towers, causing them to topple about 6,000 years ago.
However, because light from this region takes 7,000 years to reach Earth, we won't be able to capture photos of the destruction for another millenium or so.
Space is crazy, y'all.
Read the rest at The Daily Galaxy Read the rest