Tag Archives: sun

From Cassini for the Holidays: A Splendor Seldom Seen

By Guest PostDecember 20, 2012Sciencecarolyn porco, cassini spacecraft, dark side, earth, european space agency, high solar phase, in saturns shadow, jpl, NASA, orbit, planet saturn, rings, saturn, sun

PASADENA, Calif — Just in time for the holidays, NASA’s Cassini spacecraft, in orbit around Saturn for more than eight years now, has delivered another glorious, backlit view of the planet Saturn and its rings.

On Oct. 17, 2012, during its 174th orbit around the gas giant, Cassini was deliberately positioned within Saturn’s shadow, a perfect location from which to look in the direction of the sun and take a backlit view of the rings and the dark side of the planet. Looking back towards the sun is a geometry referred to by planetary scientists as “high solar phase;” near the center of your target’s shadow is the highest phase possible. This is a very scientifically advantageous and coveted viewing position, as it can reveal details about both the rings and atmosphere that cannot be seen in lower solar phase. (more…)

NASA, Texas Astronomers Find First Multi-Planet System Around a Binary Star

By Guest PostSeptember 3, 2012Scienceaustin, bill cochran, binary star, caroline caldwell, faint star, giant magellan telescope, habitable zone, harlan j smith, het, hobby eberly telescope, jerome orosz, kepler 47, kepler mission, largest telescope, m dwarf star, mcdonald observatory, michael endl, multi planet, NASA, one system, planet, primary star, san diego, secondary star, solar system, space telescope, state university, stellar eclipse, sun, tatooine, telescope, texas, transit, university, west texas, william welsh, world

FORT DAVIS, Texas — NASA’s Kepler mission has found the first multi-planet solar system orbiting a binary star, characterized in large part by University of Texas at Austin astronomers using two telescopes at the university’s McDonald Observatory in West Texas. The finding, which proves that whole planetary systems can form in a disk around a binary star, is published in today’s issue of the journal Science.

“It’s Tatooine, right?” said McDonald Observatory astronomer Michael Endl. “But this was not shown in Star Wars,” he said, referring to the periodic changes in the amount of daylight falling on a planet with two suns. Measurements of the star’s orbits showed that daylight on the planets would vary by a large margin over the 7.4-Earth-day period as the two stars completed their mutual orbits, each moving closer to, then farther from, the planets (which are themselves moving). (more…)

Scientists Discover New Trigger for Immense North Atlantic Ocean Spring Plankton Bloom

By Guest PostJuly 7, 2012Environmentadam huxtable, amala mahadevan, atlantic ocean, biological pump, bjarni saemundsson, carbon dioxide, climate, climate on earth, CO2, craig lee, diatoms, don rice, eddies, emily kallin, eric d asaro, fossil fuel, global carbon cycle, holiday fireworks, mary jane perry, michael ohmart, microscopic plants, modulate, north atlantic bloom, not sunlight, nsf, ocean physics, oceanic cycling, oxygen, photosynthesis, physical biological model, phytoplankton, research vessel, silica, sun, surface warming, university of maine, university of washington, us beachgoers, whirlpools, whoi, zooplankton

Ocean eddies help jump-start plankton blooms that spread across hundreds of square miles

On this July 4^th week, U.S. beachgoers are thronging their way to seaside resorts and parks to celebrate with holiday fireworks. But across the horizon and miles out to sea toward the north, the Atlantic Ocean’s own spring and summer ritual unfolds. It entails the blooming of countless microscopic plants, or phytoplankton.

In what’s known as the North Atlantic Bloom, an immense number of phytoplankton burst into existence, first “greening,” then “whitening” the sea as one or more species take the place of others.

What turns on this huge bloom, what starts these ocean fireworks? Is it the Sun’s warmth? (more…)

A Prime Seat to a Once-in-a-Lifetime Spectacle

By Guest PostJune 8, 2012Scienceadam block, alan strauss, astrophotographer, black void, digital slr camera, earth, east coast, England, exoplanets, expedition, filaments, Hubble Space Telescope, hydrogen alpha filter, jeremiah horrocks, liverpool, martin hamar, mount lemmon skycenter, much hoole, planet, planet venus, schulman telescope, southern arizona, sun, telescope, transit of venus, ua, venus, venus transit, village

Hosted by world-renowned astrophotographer Adam Block at the UA’s Mount Lemmon SkyCenter, a group of sky and astronomy enthusiasts watched Venus cross the sun from the highest vantage point in Southern Arizona.

On Nov. 24, 1639, in the tiny village of Much Hoole not far from Liverpool, England, a poor farmer’s son and self-taught astronomer affixed a sheet of paper in front of a makeshift telescope pointed at the sun and waited.

Thirty-five minutes before sunset, a dark, round spot appeared right next to the bright disc that was the sun’s face projected on the paper, and made Jeremiah Horrocks, only 20 years old at the time, the first known human to predict, observe and record a transit – the passage of a planet across the sun as seen from Earth.

Almost 373 years later, a group of sky enthusiasts is gathered beneath the dome of one of the University of Arizona’s observatories on Mount Lemmon just north of Tucson, Ariz. (more…)

Fossil Raindrop Impressions Imply Greenhouse Gases Loaded Early Atmosphere

By Guest PostApril 2, 2012Environmentames research center, atmosphere, atmospheric pressure, concentration, david catling, earth history, fossilized, greenhouse gases, jelte harnmeijer, latex peels, liquid water, low carbon innovation, peter polivka, pressure broadening, raindrop impression, raindrop velocity, roger buick, sanjoy som, seattle, South Africa, sun, temperature, warm temperature

In ancient Earth history, the sun burned as much as 30 percent dimmer than it does now. Theoretically that should have encased the planet in ice, but there is geologic evidence for rivers and ocean sediments between 2 billion and 4 billion years ago.

Scientists have speculated that temperatures warm enough to maintain liquid water were the result of a much thicker atmosphere, high concentrations of greenhouse gases or a combination of the two. (more…)

First Habitable-Zone super-Earth Discovered in Orbit Around a Sun-like Star

By Guest PostMarch 12, 2012Sciencealan boss, ames research center, constellation, cygnus, discovery, doppler technique, exoplanet, g5 star, Galaxy, gas giant planets, habitable zone, kepler mission, lyra, NASA, photometric data, radial velocity, space telescope, star, sun, super earth, william borucki

Washington, D.C. — NASA’s Kepler Mission has discovered the first super-Earth orbiting in the habitable zone of a star similar to the Sun. A team of researchers, including Carnegie’s Alan Boss, has discovered what could be a large, rocky planet with a surface temperature of about 72 degrees Fahrenheit, comparable to a comfortable spring day on Earth. This landmark finding will be published in The Astrophysical Journal.

The discovery team, led by William Borucki of the NASA Ames Research Center, used photometric data from the NASA Kepler space telescope, which monitors the brightness of 155,000 stars. Earth-size planets whose orbital planes are aligned such that they periodically pass in front of their stars result in tiny dimmings of their host star’s light–dimmings that can only be measured by a highly specialized space telescope like Kepler. (more…)

What Do Sunsets Look Like From Other Planets?

By Guest PostJanuary 17, 2012ScienceAlien, aspen, astrophysicist, atmosphere, colorado, conference, exoclimes, exoclimes 2012, extrasolar planets, frederic pont, fundamental problems, Galaxy, gloomy orange, hd 189, hd 189733 b, hd 209, hd 209458 b, Hubble Space Telescope, modern astronomy, neutral sodium lines, osiris, planet forming discs, planetary atmospheres, planets, sodium street lighting, solar system, spectral, sun, sunset, sunset images, transmission spectrum, university of exeter, website

A University of Exeter astrophysicist has shown what sunsets look like on planets outside our solar system.

He has worked out the colour of sunsets on two planets: HD 209458 b and HD 189733 b, known as ‘extrasolar planets’ because they are outside our solar system.

Extrasolar planets orbit stars, in a similar way to the Earth orbiting the Sun. Professor Frédéric Pont of the University of Exeter has used the extrasolar planets’ ‘transmission spectrum’, taken by the Hubble Space Telescope, to work out the colour of the ‘sunsets’ created by these stars.

Writing on the website ExoClimes.com, where he has posted the two sunset images he has produced, Professor Pont said: “Unlike its sister planet HD ’189, the planet HD ’209 (‘Osiris’) has a sunset that looks truly alien. The star is white outside the atmosphere, since its temperature is close to that of the Sun. It then acquires a bluish tinge as it sinks deeper, because the absorption by the broad wings of the neutral sodium lines (the spectral lines responsible for the gloomy orange of sodium street lighting) remove the red and orange from the star light. (more…)

Scientists Prepare to Take First-Ever Picture of a Black Hole

By Guest PostJanuary 16, 2012Scienceabyss of space, albert einstein, alma, arizona, astrophysicists, atacama large millimeter array, atmosphere, black hole, black void, center of milky way, Chile, cosmic traffic jam, dan marrone, daniel stolte, dimitrios psaltis, earth, einstein, event horizon, event horizon telescope, extreme environment, field of gravity, game changer, general relativity, global array, hawaii, haystack observatory, maelstroms, mass, massachusetts institute of technology, mauna kea, mercury, Mexico, MIT, mt graham, nothingness, optical telescopes, plasma, radio telescopes, radio waves, shadow, sheperd doeleman, south pole, space and time, steward observatory, sun, supermassive black hole, theory of general relativity, tucson, ultra precise timing, universe, university of arizona, virtual telescope, water vapor, wavelengths

*The Event Horizon Telescope is an Earth-sized virtual telescope powerful enough to see all the way to the center of our Milky Way, where a supermassive black hole will allow astrophysicists to put Einstein’s Theory of General Relativity to the test.*

Astronomers, physicists and scientists from related fields across the world will convene in Tucson, Ariz. on Jan. 18 to discuss an endeavor that only a few years ago would have been regarded as nothing less than outrageous.

The conference is organized by Dimitrios Psaltis, an associate professor of astrophysics at the University of Arizona’s Steward Observatory, and Dan Marrone, an assistant professor of astronomy at Steward Observatory. (more…)