Mercury (planet) First planet from the Sun Mercury's sidereal year (88.0 Earth's day) and sidereal day (58.65 Earth's day) is in a 3:2 ratio. This phenomenon is called spin–orbit resonance and sidereal here means "relative to the stars". Combined with its high orbital eccentricity, the planet surface has widely varying sunlight intensity and temperature, with the equator regions range from −170 °C (−270 °F) at night to 420 °C (790 °F) during sunlight. Nomenclature Physical characteristics Internal structure Surface geology Impact basins and craters Overhead view of Caloris Basin Perspective view of Caloris Basin – high (red); low (blue) Plains Compressional features Volcanism Surface conditions and exosphere Magnetic field and magnetosphere Orbit, rotation, and longitude Orbit of Mercury (2006) Animation of Mercury's and Earth's revolution around the Sun Longitude convention Spin-orbit resonance Advance of perihelion Observation Observation history Ancient astronomers Ground-based telescopic research Mariner 10 BepiColombo
Pulsar The precise periods of pulsars makes them useful tools. Observations of a pulsar in a binary neutron star system were used to indirectly confirm the existence of gravitational radiation. The first extrasolar planets were discovered around a pulsar, PSR B1257+12. Certain types of pulsars rival atomic clocks in their accuracy in keeping time. History of observation[edit] Discovery[edit] The first pulsar was observed on November 28, 1967, by Jocelyn Bell Burnell and Antony Hewish.[1][2][3] They observed pulses separated by 1.33 seconds that originated from the same location on the sky, and kept to sidereal time. The word "pulsar" is a contraction of "pulsating star",[7] and first appeared in print in 1968: An entirely novel kind of star came to light on Aug. 6 last year and was referred to, by astronomers, as LGM (Little Green Men). Milestones[edit] In 1974, Joseph Hooton Taylor, Jr. and Russell Hulse discovered for the first time a pulsar in a binary system, PSR B1913+16. Nomenclature[edit]
Phobos (moon) Phobos (systematic designation: Mars I) is the larger and closer of the two natural satellites of Mars. Both moons were discovered in 1877. Phobos has dimensions of 27 × 22 × 18 km,[1] and is too small to be rounded under its own gravity. Its surface area is slightly less than the land area of Delaware. Phobos does not have an atmosphere due to low mass and low gravity.[10] It is one of the least reflective bodies in the Solar System. Spectroscopically it appears to be similar to the D-type asteroids,[11] and is apparently of composition similar to carbonaceous chondrite material.[12] Phobos's density is too low to be solid rock, and it is known to have significant porosity.[13][14][15] These results led to the suggestion that Phobos might contain a substantial reservoir of ice. The unique Kaidun meteorite is thought to be a piece of Phobos, but this has been difficult to verify since little is known about the detailed composition of the moon.[25][26]
Black hole A black hole is defined as a region of spacetime from which gravity prevents anything, including light, from escaping.[1] The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole.[2] Around a black hole, there is a mathematically defined surface called an event horizon that marks the point of no return. The hole is called "black" because it absorbs all the light that hits the horizon, reflecting nothing, just like a perfect black body in thermodynamics.[3][4] Quantum field theory in curved spacetime predicts that event horizons emit radiation like a black body with a finite temperature. This temperature is inversely proportional to the mass of the black hole, making it difficult to observe this radiation for black holes of stellar mass or greater. Objects whose gravity fields are too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace. History General relativity
Jupiter Structure Jupiter is composed primarily of gaseous and liquid matter. It is the largest of four gas giants as well as the largest planet in the Solar System with a diameter of 142,984 km (88,846 mi) at its equator. The density of Jupiter, 1.326 g/cm3, is the second highest of the gas giants, but lower than for any of the four terrestrial planets. Composition Jupiter's upper atmosphere is composed of about 88–92% hydrogen and 8–12% helium by percent volume or fraction of gas molecules. Based on spectroscopy, Saturn is thought to be similar in composition to Jupiter, but the other gas giants Uranus and Neptune have relatively much less hydrogen and helium.[21] Because of the lack of atmospheric entry probes, high-quality abundance numbers of the heavier elements are lacking for the outer planets beyond Jupiter. Mass Jupiter's diameter is one order of magnitude smaller (×0.10045) than the Sun, and one order of magnitude larger (×10.9733) than the Earth. Internal structure Atmosphere Cloud layers
Burn notice: NASA discovers that fireproof materials ignite in space Still frames showing a piece of cotton-fiberglass, similar to the cotton civilian clothing worn by astronauts, burning from bottom-to-top during a space station experiment (Credit: Paul Ferkul/NASA/BASS). High above the Earth, astronauts aboard the International Space Station are playing with fire — very carefully. By lighting controlled fires and watching them burn, the Expedition 35 team is learning how to prevent accidental blazes from breaking out aboard the station and other spacecraft — a nightmare scenario that could put not only lives, but the very future of human spaceflight at risk. "We can certainly make things not flammable on Earth, but in space, that changes," said Dr. Paul Ferkul, a NASA scientist whose experiment recently found that a fire-resistant fabric similar to astronaut clothing actually ignites in space. "in space, [fireproofing] changes." "more dangerous or less dangerous in space?" "This type of situation could occur."
Navy's New Slab of Precision-Honed Granite--the World's Largest--Will Improve Microgravity Studies Granite Slab This may look like a slab of rock sitting in a room. But it's actually an ultra-precise microgravity laboratory, honed for the U.S. Navy. It will be used to emulate the inertia of space in the lab, testing things like the Front-End Robotic Enabling Near-Term Demonstration (FREND) arm, seen here with the slab. Testing how objects act in microgravity is not limited to astronauts on the space station. The Navy just got a new 75,000-pound slab of granite, honed to near perfection at just plus or minus 0.0018 inches of irregularity across its entire 300-square-foot surface. It will help scientists emulate the motion of objects in space, which they’ll do by floating objects on air above its frictionless surface — similar to how an air hockey table works. One goal is to figure out how to capture and dock with free-floating spacecraft. [ U.S.
Mystery photo from Mars rover Curiosity explained The mystery of the blotch on one of the Mars rover Curiosity's photos appears to have been solved. Engineers said Friday that the Curiosity rover happened to catch a picture of its own ride crash-landing on Mars — a blink-of-an-eye serendipity that some dismissed as a statistical impossibility, but appears to have been confirmed by a thorough review of landing data. The final seconds of Curiosity’s eight-month-plus journey to Mars called for a spacecraft to lower the rover to the surface using a “sky crane” — three ropes. The ropes were then cut, and the last of the spacecraft, known as the “descent stage,” cast itself toward the horizon. It crash-landed, on purpose, about 2,000 feet away. A low-resolution photograph that Curiosity took seconds after landing Sunday night arrived immediately at La Cañada Flintridge’s Jet Propulsion Laboratory, which is managing the $2.5-billion mission for NASA. The photograph captured a pyramid-shaped blotch on the horizon. --Scott Gold
Awesome spaceship that discovered hundreds of new planets may soon be space junk A recent cover from The Economist imagines prime minister Shinzo Abe as Superman . Ok, Abe in a crimson lounge singer jacket is cringe-worthy; so is the “super yen” emblazoned on his chest. But still, the image captures a big misunderstanding about Abenomics: that it’s all about the weakening of the yen. The point of Abenomics is to beat deflation in Japan, not drive up exports to juice growth. Right now, the bulk of those rising imports are probably goods that are priced in dollars—things like commodities, which make up around half of Japan’s imports by value. Case in point, from a Bloomberg report today : Apple is now selling its fanciest iPad model for ¥49,800 ($493), a 16% increase from its previous price of ¥42,800, or about $424. Some think that this amounts to “importing inflation”—a purported cure for deflation. But here’s why that won’t work: Yes, a strong yen coupled with deflation boosted purchasing power in Japan.
Record-setting blast of gamma rays from a dying star | NASA said late in the day yesterday (May 3, 2013) that a record-setting blast of gamma rays from a dying star in a distant galaxy has wowed astronomers around the world. The eruption is a gamma-ray burst (GRB), one of the universe’s most luminous explosions, thought to take place when supernovae erupt in distant galaxies. This particular GRB is designated GRB 130427A. The animation above shows how the sky looks at gamma-ray energies above 100 million electron volts (MeV) with a view centered on the north galactic pole. We have waited a long time for a gamma-ray burst this shockingly, eye-wateringly bright. The burst subsequently was detected in optical, infrared and radio wavelengths by ground-based observatories. Astronomers think most [gamma rays bursts] occur when massive stars run out of nuclear fuel and collapse under their own weight. Read more about the shockingly, eye-wateringly bright gamma ray burst from NASA