In 1972, the late, world famous astronomer Carl Sagan and his colleague George Mullen formulated "The faint early sun paradox. " The paradox consisted in that the earth's climate has been fairly constant during almost four of the four and a half billion years that the planet has been in existence, and this despite the fact that radiation from the sun has increased by 25-30 percent.
Heavens
Since Galileo first pointed a telescope at the sky 400 years ago, a myriad of technological advances have allowed astronomers to look at very faint objects, very distant objects, and even light that's invisible to the human eye. Yet, one aspect usually remains out of reach - the benefit of a 3-D perspective.
Our telescopes show the Milky Way galaxy only as it appears from one vantage point: our solar system. Now, using a simple but powerful technique, a group of astronomers led by Armin Rest of Harvard University has seen an exploding star or supernova from several angles.
Gum 19 is located in the direction of the constellation Vela (the Sail) at a distance of approximately 22 000 light years. The Gum 19 moniker derives from a 1955 publication by the Australian astrophysicist Colin S. Gum that served as the first significant survey of so-called HII (read "H-two") regions in the southern sky. HII refers to hydrogen gas that is ionised, or energised to the extent that the hydrogen atoms lose their electrons. Such regions emit light at well-defined wavelengths (or colours), thereby giving these cosmic clouds their characteristic glow.
Having been hit by two tropical cyclones so far this season, Queensland had been the center of tropical cyclone activity, but with the recent arrival of Tropical Cyclone Paul, it is now the Northern Territory's turn to experience heavy rains and gusty winds.
GREENBELT, Md. – The cosmos is filled with color, and color is a key in determining age, chemical composition and how far objects are from Earth. To help identify these colors and objects the James Webb Space Telescope will be using a spectrograph called NIRSpec. Recently, the engineering test unit for the Webb telescope's Near-Infrared Spectrograph (NIRSpec) instrument arrived at NASA's Goddard Space Flight Center, Greenbelt, Md. from its manufacturer in Germany for preliminary testing.
Washington, March 30, 2010 – Misunderstandings about proper use of antibiotics have the potential to spread widely through social networks such as Twitter, according to a report in the April issue of AJIC: American Journal of Infection Control, the official publication of the Association for Professionals in Infection Control and Epidemiology, Inc. (APIC).
On 30 and 31 March a strategic international workshop on the Square Kilometre Array (SKA) will seek to identify the major economical and societal benefits of large-scale scientific research infrastructure investments.
The SKA is a USD 1 billion+ international project to create a radio telescope incorporating a receiving surface of a million square metres, fifty times larger than the biggest receiving surface now in existence. This huge surface will be composed of many small antennas, divided into a dense inner core array which becomes more diffuse with increasing radius.
Despite the fact that bats are active after sunset, they rely on the sun as their most trusted source of navigation. Researchers from the Max Planck Institute for Ornithology found that the greater mouse-eared bat orients itself with the help of the Earth's magnetic field at night and calibrates this compass to the sun's position at sunset.
The highest-resolution-yet temperature map and images of Saturn's icy moon Mimas obtained by NASA's Cassini spacecraft reveal surprising patterns on the surface of the small moon, including unexpected hot regions that resemble "Pac-Man" eating a dot, and striking bands of light and dark in crater walls.
"Other moons usually grab the spotlight, but it turns out Mimas is more bizarre than we thought it was," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "It has certainly given us some new puzzles."
Tropical Storm Omais is fading fast in the northwestern Pacific Ocean, and will dissipate over the weekend according to the Joint Typhoon Warning Center. When NASA's Aqua satellite flew over Omais late on March 25, it already showed signs of falling apart.
This isn't a good weekend for keeping tropical cyclones alive, as Tropical Storm Omais is becoming extra-tropical in the northwestern Pacific Ocean and Tropical Storm Imani appears doomed over the weekend in the Southern Indian Ocean.
Tampa, FL (March 24, 2010) -- A sun protection intervention program that encouraged fourth-graders to wear hats outdoors as a skin cancer prevention measure significantly increased hat use at school, a study by researchers at the University of South Florida College of Medicine found. The program, however, had no effect on self-reported hat use at home or on measures of skin pigmentation.
Tampa, FL (March 24, 2010) -- A sun protection intervention program that encouraged fourth-graders to wear hats outdoors as a skin cancer prevention measure significantly increased hat use at school, a study by researchers at the University of South Florida College of Medicine found. The program, however, had no effect on self-reported hat use at home or on measures of skin pigmentation.
New Haven, Conn.—Supermassive black holes found at the centers of distant galaxies undergo huge growth spurts as a result of galactic collisions, according to a new study by astronomers at Yale University and the University of Hawaii. Their findings appear in the March 25 edition of Science Express.
Tropical storm Omais has run into wind shear in the northwestern Pacific Ocean, but as it has weakened overnight it has also doubled in size. NASA's Aqua satellite has captured both infrared and visible images early this morning of the larger Omais.
Late yesterday, March 24, Omais strengthened to (63 mph) 55 knots and now that it has run into an environment with stronger wind shear, it has already weakened. The wind shear has increased because of the approach of a frontal system which is currently about 215 nautical miles northwest of the storm.