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Archive for the ‘ASTRONOMY’ Category

How NASA’s Spitzer Space Telescope works

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An infographic showing how NASA’s Spitzer Space Telescope works with ground-based telescopes to find distant exoplanets, using a technique called microlensing.
Read more at space.com

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April 26, 2015 at 7:25 am

Beyond the New Horizon: The Future of Pluto

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Best fit lines for functions as determined by the Pluto masses on left, and Pluto and Planet X masses on the right

Best fit lines for functions as determined by the Pluto masses on left, and Pluto and Planet X
masses on the right

Michael B. Lund
Since its discovery in 1930, Pluto’s mass has been a value that has repeatedly been calculated.
Additionally, the search for Planet X prior to Pluto’s discovery results in mass calculations that date back several decades earlier. Over its observed history, the mass of Pluto has consistently decreased. We reassess earlier predictions of Pluto’s fate, and rule out the hypothesis that Pluto’s mass has been constant over the last century.
We are able to fit linear and quadratic equations to Pluto’s mass as a function of both time and distance.
The observations that will be made by New Horizons will help to determine if we can expect Pluto to continue to shrink until it has negative mass, or if it will begin to increase in mass again…
… Read more at http://arxiv.org/pdf/1504.00630v1.pdf

Written by physicsgg

April 3, 2015 at 8:07 pm

Posted in ASTRONOMY, ASTROPHYSICS

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The dark side of cosmology: Dark matter and dark energy

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The multiple components that compose our universe. Dark energy comprises 69% of the mass energy density of the universe, dark matter comprises 25%, and “ordinary” atomic matter makes up 5%. There are other observable subdominant components: Three different types of neutrinos comprise at least 0.1%, the cosmic background radiation makes up 0.01%, and black holes comprise at least 0.005%.

The multiple components that compose our universe.
Dark energy comprises 69% of the mass energy density of the universe, dark matter comprises 25%, and “ordinary” atomic matter makes up 5%. There are other observable subdominant components: Three different types of neutrinos comprise at least 0.1%, the cosmic background radiation makes up 0.01%, and black holes comprise at least 0.005%.

A simple model with only six parameters (the age of the universe, the density of atoms, the density of matter, the amplitude of the initial fluctuations, the scale dependence of this amplitude, and the epoch of first star formation) fits all of our cosmological data . Although simple, this standard model is strange. The model implies that most of the matter in our Galaxy is in the form of “dark matter,” a new type of particle not yet detected in the laboratory, and most of the energy in the universe is in the form of “dark energy,” energy associated with empty space. Both dark matter and dark energy require extensions to our current understanding of particle physics or point toward a breakdown of general relativity on cosmological scales…
…Read more at http://www.sciencemag.org/content/347/6226/1100.full

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March 6, 2015 at 5:58 pm

Why isn’t the universe as bright as it should be?

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Study explains why galaxies don’t churn out as many stars as they should.

A handful of new stars are born each year in the Milky Way, while many more blink on across the universe. But astronomers have observed that galaxies should be churning out millions more stars, based on the amount of interstellar gas available.
Now researchers from MIT, Columbia University, and Michigan State University have pieced together a theory describing how clusters of galaxies may regulate star formation. They describe their framework this week in the journal Nature.
When intracluster gas cools rapidly, it condenses, then collapses to form new stars. Scientists have long thought that something must be keeping the gas from cooling enough to generate more stars — but exactly what has remained a mystery.
For some galaxy clusters, the researchers say, the intracluster gas may simply be too hot — on the order of hundreds of millions of degrees Celsius. Even if one region experiences some cooling, the intensity of the surrounding heat would keep that region from cooling further — an effect known as conduction.
“It would be like putting an ice cube in a boiling pot of water — the average temperature is pretty much still boiling,” says Michael McDonald, a Hubble Fellow in MIT’s Kavli Institute for Astrophysics and Space Research. “At super-high temperatures, conduction smooths out the temperature distribution so you don’t get any of these cold clouds that should form stars.” Read the rest of this entry »

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March 5, 2015 at 1:06 pm

Posted in ASTRONOMY, COSMOLOGY

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85 Years after Pluto’s Discovery, NASA’s New Horizons Spots Small Moons Orbiting Pluto

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The moons Nix and Hydra are visible in a series of images taken by the New Horizons spacecraft. Image Credit: NASA/Johns Hopkins APL/Southwest Research Institute

The moons Nix and Hydra are visible in a series of images taken by the New Horizons spacecraft.
Image Credit: NASA/Johns Hopkins APL/Southwest Research Institute

Exactly 85 years after Clyde Tombaugh’s historic discovery of Pluto, the NASA spacecraft set to encounter the icy planet this summer is providing its first views of the small moons orbiting Pluto.

The moons Nix and Hydra are visible in a series of images taken by the New Horizons spacecraft from Jan. 27-Feb. 8, at distances ranging from about 125 million to 115 million miles (201 million to 186 million kilometers). The long-exposure images offer New Horizons’ best view yet of these two small moons circling Pluto which Tombaugh discovered at Lowell Observatory in Flagstaff, Arizona, on Feb. 18, 1930.

“Professor Tombaugh’s discovery of Pluto was far ahead its time, heralding the discovery of the Kuiper Belt and a new class of planet,” says Alan Stern, New Horizons principal investigator from Southwest Research Institute, Boulder, Colorado. “The New Horizons team salutes his historic accomplishment.”

Assembled into a seven-frame movie, the new images provide the spacecraft’s first extended look at Hydra (identified by a yellow diamond ) and its first-ever view of Nix (orange diamond). The right-hand image set has been specially processed to make the small moons easier to see. “It’s thrilling to watch the details of the Pluto system emerge as we close the distance to the spacecraft’s July 14 encounter,” says New Horizons science team member John Spencer, also from Southwest Research Institute. “This first good view of Nix and Hydra marks another major milestone, and a perfect way to celebrate the anniversary of Pluto’s discovery.”

nh_lorri_4x4

Assembled into a seven-frame movie, the new images provide the spacecraft’s first extended look at Hydra (identified by a yellow diamond ) and its first-ever view of Nix (orange diamond). Image Credit: NASA/Johns Hopkins APL/Southwest Research Institute

These are the first of a series of long-exposure images that will continue through early March, with the purpose of refining the team’s knowledge of the moons’ orbits. Each frame is a combination of five 10-second images, taken with New Horizons’ Long-Range Reconnaissance Imager (LORRI) using a special mode that combines pixels to increase sensitivity at the expense of resolution. At left, Nix and Hydra are just visible against the glare of Pluto and its large moon Charon, and the dense field of background stars. The bright and dark streak extending to the right of Pluto is an artifact of the camera electronics, resulting from the overexposure of Pluto and Charon. As can be seen in the movie, the spacecraft and camera were rotated in some of the images to change the direction of this streak, in order to prevent it from obscuring the two moons.

The right-hand images have been processed to remove most of Pluto and Charon’s glare, and most of the background stars. The processing leaves blotchy and streaky artifacts in the images, and also leaves a few other residual bright spots that are not real features, but makes Nix and Hydra much easier to see. Celestial north is inclined 28 degrees clockwise from the “up” direction in these images.

Nix and Hydra were discovered by New Horizons team members in Hubble Space Telescope images taken in 2005. Hydra, Pluto’s outermost known moon, orbits Pluto every 38 days at a distance of approximately 40,200 miles (64,700 km), while Nix orbits every 25 days at a distance of 30,260 miles (48,700 km). Each moon is probably between 25-95 miles (approximately 40- 150 kilometers) in diameter, but scientists won’t know their sizes more precisely until New Horizons obtains close-up pictures of both of them in July. Pluto’s two other small moons, Styx and Kerberos, are still smaller and too faint to be seen by New Horizons at its current range to Pluto; they will become visible in the months to come.

The Johns Hopkins University Applied Physics Laboratory manages the New Horizons mission for NASA’s Science Mission Directorate in Washington. Alan Stern, of the Southwest Research Institute (SwRI), headquartered in San Antonio, is the principal investigator and leads the mission. SwRI leads the science team, payload operations, and encounter science planning. New Horizons is part of the New Frontiers Program managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama. APL designed, built and operates the spacecraft.

Read more at www.nasa.gov

Written by physicsgg

February 18, 2015 at 6:02 pm

Posted in ASTRONOMY, ASTROPHYSICS, SPACE

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New space telescope concept could image objects at far higher resolution than Hubble

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A new orbiting telescope concept developed at CU-Boulder could allow scientists to image objects in space or on Earth at hundreds of times the resolution of the Hubble Space Telescope. Image courtesy NASA

A new orbiting telescope concept developed at CU-Boulder could allow scientists to image objects in space or on Earth at hundreds of times the resolution of the Hubble Space Telescope. Image courtesy NASA

University of Colorado Boulder researchers will update NASA officials next week on a revolutionary space telescope concept selected by the agency for study last June that could provide images up to 1,000 times sharper than the Hubble Space Telescope.

CU-Boulder Professor Webster Cash said the instrument package would consist of an orbiting space telescope and an opaque disk in front of it that could be up to a half mile across. According to Cash, diffracted light waves from a target star or other space object would bend around the edges of the disk and converge in a central point. That light would then be fed into the orbiting telescope to provide high-resolution images, he said.

The new telescope concept, named the Aragoscope after French scientist Francois Arago who first detected diffracted light waves around a disk, could allow scientists to image space objects like black hole “event horizons” and plasma swaps between stars, said Cash of CU-Boulder’s Center for Astrophysics and Space Astronomy. The novel telescope system also could point toward Earth and image objects as small as a rabbit, giving it the ability to hunt for lost campers in the mountains, he said. Read the rest of this entry »

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January 28, 2015 at 8:44 am

Posted in ASTRONOMY, ASTROPHYSICS

Are Aliens Watching Old TV Shows?

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Written by physicsgg

January 20, 2015 at 6:04 am

Missions Take an Unparalleled Look into Superstar Eta Carinae

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Read more at www.nasa.gov

Written by physicsgg

January 7, 2015 at 8:05 pm

Posted in ASTRONOMY, ASTROPHYSICS