Tag Archives: earth

Apollo 15 from above

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Apollo 15 from unusually low altitude – Apollo 15 landing site imaged from an altitude of 25 km (M175252641L,R) allowing an even higher resolution view! The Lunar Roving Vehicle (LRV) is parked to the far right, and the Lunar Module descent stage is in the center, LRV tracks indicated with arrows [NASA/GSFC/Arizona State University].

The Apollo 15 Lunar Module (LM) Falcon set down on the Hadley plains (26.132°N, 3.634°E) a mere 2 kilometers from Hadley Rille. The goals: sample the basalts that compose the mare deposit, explore a lunar rille for the first time, and search for ancient crustal rocks. Additionally, Dave Scott and Jim Irwin deployed the third Apollo Lunar Surface Experiments Package (ALSEP) and unveiled the first Lunar Roving Vehicle (LRV). The ALSEP consisted of several experiments that were powered by a Radioisotope Thermoelectric Generator (RTG) and sent back valuable scientific data to the Earth for over six years after the astronauts left. This new LROC NAC image taken from low altitude shows the hardware and tracks in even more detail. … (Lunar Pioneer)

The ten year watch

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In the early hours of 1 March 2002, the largest Earth observation satellite ever built soared into orbit from ESA’s launch base in Kourou, French Guiana. For a decade, Envisat has been keeping watch over our planet.

The eight-tonne satellite has doubled its planned five-year lifetime, circling Earth more than 50 000 times. With ten sophisticated optical and radar sensors, the satellite is continuously observing and monitoring Earth’s land, atmosphere, oceans and ice caps. An estimated 2000 scientific publications have been based on this information. … (ESA)

Take a deep breath

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NASA’s Cassini spacecraft has “sniffed” molecular oxygen ions around Saturn’s icy moon Dione for the first time, confirming the presence of a very tenuous atmosphere. The oxygen ions are quite sparse – one for every 0.67 cubic inches of space (one for every 11 cubic centimeters of space) or about 2,550 per cubic foot (90,000 per cubic meter) – show that Dione has an extremely thin neutral atmosphere.

At the Dione surface, this atmosphere would only be as dense as Earth’s atmosphere 300 miles (480 kilometers) above the surface. The detection of this faint atmosphere, known as an exosphere, is described in a recent issue of the journal Geophysical Research Letters.

“We now know that Dione, in addition to Saturn’s rings and the moon Rhea, is a source of oxygen molecules,” said Robert Tokar, a Cassini team member based at Los Alamos National Laboratory, Los Alamos, N.M., and the lead author of the paper. “This shows that molecular oxygen is actually common in the Saturn system and reinforces that it can come from a process that doesn’t involve life.”

Dione’s oxygen appears to derive from either solar photons or energetic particles from space bombarding the moon’s water ice surface and liberating oxygen molecules, Tokar said. But scientists will be looking for other processes, including geological ones, that could also explain the oxygen. … (Cassini)

Somewhat closer to home

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Neil Armstrong, the first person to set foot on the moon, thinks humanity should stop neglecting the space environment much closer to Earth.

The United States dropped most of its test flights in the stratosphere and suborbital space after figuring out how to send humans to low-Earth orbit and the moon, said Armstrong, who stepped onto the lunar surface during NASA’s Apollo 11 mission in July 1969. He thinks it’s time for that to change.

“In the suborbital area, there are a lot of things to be done,” Armstrong said here Monday (Feb. 27) during a presentation at the 2012 Next-Generation Suborbital Researchers Conference (NSRC-2012). “This is an area that has been essentially absent for about four decades, since the X-15 finished its job.”

The X-15 was a rocket plane that took to the skies 199 times between 1959 and 1968, setting numerous speed and altitude records along the way. Armstrong was at the controls for some of those flights; before becoming an astronaut in 1962, the moonwalker was a test pilot for NASA and its predecessor institution, the National Advisory Committee for Aeronautics.

The test flights of the X-15 and other experimental craft of the era helped pave the way for future vehicles, such as NASA’s iconic space shuttle. Further investigation and exploitation of suborbital space — this time led not by the government but by private industry — could provide more technological and economic benefits to the country, Armstrong said. … (SPACE.com)

A drama in 3D

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At the turn of the 19th century, the binary star system Eta Carinae was faint and undistinguished. In the first decades of the century, it became brighter and brighter, until, by April 1843, it was the second brightest star in the sky, outshone only by Sirius (which is almost a thousand times closer to Earth). In the years that followed, it gradually dimmed again and by the 20th century was totally invisible to the naked eye.

The star has continued to vary in brightness ever since, and while it is once again visible to the naked eye on a dark night, it has never again come close to its peak of 1843.

The larger of the two stars in the Eta Carinae system is a huge and unstable star that is nearing the end of its life, and the event that the 19th century astronomers observed was a stellar near-death experience. Scientists call these outbursts supernova impostor events, because they appear similar to supernovae but stop just short of destroying their star. … (Hubble)

First, create debris, second, clean it up

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In the future, hopefully we will travel farther from Earth. At the same time a lot of satellites will become smaller. And when their end has come, they should be cleaned up.

For mini-satellites, read the following article on the JAXA site.

An ultra-small satellite, so-called micro or nano-satellite, is one weighing less than 100kg in total mass. In this article, I will discuss specifically satellites of under 50kg. R&D on ultra-small satellites is being advanced at a remarkable pace across the world. In Japan, the laboratories of the University of Tokyo and Tokyo Institute of Technology started first to develop cansats weighing several 100 grams and lately succeeded in on-orbit demonstrations of 1kg-class cubesats for the first time in the world. Since then, activities on the satellites have started a trend. Today, energetic and promising young people from many universities and technical colleges have entered the world of the ultra-small satellite. As a result, new fields of space engineering are being explored…. (JAXA)

And if you want more info about the cleanup, here’s a Swiss initiative.

By the middle of the decade, it may be possible to salvage satellites that run out of fuel or suffer minor malfunctions in orbit.

Canada-based aerospace firm MacDonald, Dettwiler and Associates Ltd. is designing a spacecraft that will serve as an orbiting gas station and mechanic. The robotic vehicle will be able to top off satellites’ fuel tanks and perform minor repairs as needed. MDA’s first servicing satellite could be ready to go by 2015 or 2016, if a suitable customer steps up, company officials said.

“The future for space servicing is definitely now,” Dan King, director of orbital robotics at MDA, said during a presentation with NASA’s Future In-Space Operations working group yesterday (Feb. 15). “The key technologies that are needed to do some fundamental operational-type services are here.” … (SPACE.com)

It’s great to see it all come together in the future.

Steamy windows for possible settlers

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This looks like a mighty cool – hot – planet. A waterworld under an atmosphere of water vapor. There could be boiling some life over there! It’s clear (yet damp) that there’s a whole lot more to (exo)planets than the casual rock- and gas planets we have in our neighborhood:

Observations by the NASA/ESA Hubble Space Telescope have come up with a new class of planet, a waterworld enshrouded by a thick, steamy atmosphere. It’s smaller than Uranus but larger than Earth.

An international team of astronomers led by Zachory Berta of the Harvard-Smithsonian Center for Astrophysics (CfA) made the observations of the planet GJ 1214b.

“GJ 1214b is like no planet we know of,” Berta said. “A huge fraction of its mass is made up of water.”

The ground-based MEarth Project, led by CfA’s David Charbonneau, discovered GJ 1214b in 2009. This super-Earth is about 2.7 times Earth’s diameter and weighs almost seven times as much. It orbits a red-dwarf star every 38 hours at a distance of 2 million kilometers, giving it an estimated temperature of 230 degrees Celsius.

In 2010, CfA scientist Jacob Bean and colleagues reported that they had measured the atmosphere of GJ 1214b, finding it likely that it was composed mainly of water. However, their observations could also be explained by the presence of a planet-enshrouding haze in GJ 1214b’s atmosphere. … (Hubble)