Tuesday, May 23, 2017

A View Towards M101

Big, beautiful spiral galaxy M101 is one of the last entries in Charles Messier's famous catalog, but definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way galaxy. M101 was also one of the original spiral nebulae observed by Lord Rosse's large 19th century telescope, the Leviathan of Parsontown. M101 shares this modern telescopic field of view with spiky foreground stars within the Milky Way, and more distant background galaxies. The colors of the Milky Way stars can also be found in the starlight from the large island universe. Its core is dominated by light from cool yellowish stars.Along its grand spiral arms are the blue colors of hotter, young stars mixed with obscuring dust lanes and pinkish star forming regions. Also known as the Pinwheel Galaxy, M101 lies within the boundaries of the northern constellation Ursa Major, about 25 million light-years away.
Image Credit & CopyrightLaszlo Bagi

In the Center of Lagoon Nebula

The center of the Lagoon Nebula is a whirlwindof spectacular star formation. Visible on the lower left, at least two long funnel-shaped clouds, each roughly half a light-year long, have been formed by extreme stellar winds and intense energetic starlight. The tremendously bright nearby star, Hershel 36, lights the area. Vast walls of dust hide and redden other hot young stars. As energy from these stars pours into the cool dust and gas, large temperature differences in adjoining regions can be created generating shearing winds which may cause the funnels. This picture, spanning about 5 light years, was taken in 1995 by the orbiting Hubble Space Telescope. The Lagoon Nebula, also known as M8, lies about 5000 light years distant toward the constellation of Sagittarius.
Image Credit: Hubble, A. Caulet (ST-ECF, ESA),NASA

Sunday, May 7, 2017

Galaxy Cluster Abell 370 and Beyond

Some 4 billion light-years away, massive galaxy cluster Abell 370 only appears to be dominated by two giant elliptical galaxies and infested with faint arcs in this sharp Hubble Space Telescope snapshot. The fainter, scattered bluish arcs along with the dramatic dragon arc below and left of center are images of galaxies that lie far beyond Abell 370. About twice as distant, their otherwise undetected light is magnified and distorted by the cluster's enormous gravitational mass, dominated by unseen dark matter. Providing a tantalizing glimpse of galaxies in the early universe, the effect is known as gravitational lensing. A consequence of warped spacetime it was first predicted by Einstein a century ago. Far beyond the spiky foreground Milky Way star at lower right, Abell 370 is seen toward the constellation Cetus, the Sea Monster. It is the last of six galaxy clusters imaged in the recently concluded Frontier Fieldsproject.
Image Credit: NASAESA, Jennifer Lotz and theHFF Team (STScI)

The Perseus Cluster Waves

The cosmic swirl and slosh of giant waves in an enormous reservoir of glowing hot gas are traced in this enhanced X-ray image from theChandra Observatory. The frame spans over 1 million light-years across the center of the nearby Perseus Galaxy Cluster, some 240 million light-years distant. Like other clusters of galaxies, most of the observable mass in the Perseus cluster is in the form of the cluster-filling gas. With temperatures in the tens of millions of degrees, the gas glows brightly in X-rays. Computer simulations can reproduce details of the structures sloshing through the Perseus cluster's X-ray hot gas, including the remarkable concave bay seen below and left of center. About 200,000 light-years across, twice the size of the Milky Way, the bay's formation indicates that Perseus itself was likely grazed by a smaller galaxy cluster billions of years ago.
For image credit and copyright guidance, please visit the image websitehttp://antwrp.gsfc.nasa.gov/apod/ap170504.html

Chandra X-ray Observatory

Illustration of Earth-Size 'Tatooine' Planet

With two suns in its sky, Luke Skywalker's home planet Tatooine in "Star Wars" looks like a parched, sandy desert world. In real life, thanks to observatories such as NASA's Kepler space telescope, we know that two-star systems can indeed support planets, although planets discovered so far around double-star systems are large and gaseous. Scientists wondered: If an Earth-size planet were orbiting two suns, could it support life?

It turns out, such a planet could be quite hospitable if located at the right distance from its two stars, and wouldn't necessarily even have deserts. In a particular range of distances from two sun-like host stars, a planet covered in water would remain habitable and retain its water for a long time, according to an April 6, 2017 study in the journal Nature Communications.

This illustration shows a hypothetical planet covered in water around the binary star system of Kepler-35A and B. In reality, the stellar pair Kepler-35A and B host a planet called Kepler-35b, a giant planet about eight times the size of Earth, with an orbit of 131.5 Earth days. For their study, researchers neglected the gravitational influence of this planet and added a hypothetical water-covered, Earth-size planet around the Kepler-35 A and B stars. They examined how this planet’s climate would behave as it orbited the host stars with periods between 341 and 380 days.

More: Earth-Sized 'Tatooine' Planets Could Be Habitable

Image Credit: NASA/JPL-Caltech


Wednesday, May 3, 2017

Cassini Looks out from Saturn

This is what Saturn looks like from inside the rings. Last week, for the first time, NASA directed the Cassini spacecraft to swoop between Saturn and its rings. During the dive, the robotic spacecraft took hundreds of images showing unprecedented detail for structures in Saturn's atmosphere. Looking back out, however, the spacecraft was also able to capture impressive vistas. In the featured imagetaken a few hours before closest approach,Saturn's unusual northern hexagon is seen surrounding the North Pole. Saturn's C ring is the closest visible, while the dark Cassini Division separates the inner B ring from the outer A. A close inspection will find the twosmall moons that shepherd the F-ring, the farthest ring discernable. This image is raw and will be officially verified, calibrated and released at a later date. Cassini remains on schedule toend its mission by plunging into Saturn's atmosphere on September 15.
Image Credit: NASAJPL-CaltechSpace Science Institute


Cooling Neutron Star

The bright source near the center is a neutron star, the incredibly dense, collapsed remains of a massive stellar core. Surrounding it issupernova remnant Cassiopeia A (Cas A), acomfortable 11,000 light-years away. Light from the Cas A supernova, the death explosion of a massive star, first reached Earth about 350 years ago. The expanding debris cloud spans about 15 light-years in this composite X-ray/optical image. Still hot enough to emit X-rays, Cas A's neutron star is cooling. In fact, years of observations with the orbiting Chandra X-ray Observatory find that the neutron star is cooling rapidly -- so rapidly that researchers suspect a large part of the neutron star's core is forming a frictionless neutron superfluid. The Chandra results represent the first observational evidence for this bizarre state of neutron matter.
Image Credit: X-ray:NASA/CXC/UNAM/Ioffe/D.PageP. Shternin et al; Optical: NASA/STScI
Illustration: NASA/CXC/M. Weiss