Sun Spot And Its Effects


A sunspot is an area on the Sun's surface (photosphere) that is marked by intense magnetic activity, which inhibits convection, forming areas of reduced surface temperature. They can be visible from Earth without the aid of a telescope. Although they are at temperatures of roughly 5,000–6,500 K, the contrast with the surrounding material at about 5,800 K leaves them clearly visible as dark spots, as the intensity of a heated black body (closely approximated by the photosphere) is a function of T (temperature) to the fourth power. If a sunspot were isolated from the surrounding photosphere it would be brighter than an electric arc.

Sunspots, being the manifestation of intense magnetic activity, host secondary phenomena such as coronal loops and reconnection events. Most solar flares and coronal mass ejections originate in magnetically active regions around visible sunspot groupings. Similar phenomena indirectly observed on stars are commonly called starspots and both light and dark spots have been measuredFile:Sun projection with spotting-scope.jpg

The sun emitted an extremely powerful flare toward Earth on 1 September 1859. It interrupted electrical telegraph service and caused visible Aurora Borealis as far south as Havana, Hawaii, and Rome with similar activity in the southern hemisphere.

The most powerful flare observed by satellite instrumentation began on 4 November 2003 at 19:29 UTC, and saturated instruments for 11 minutes. Region 486 has been estimated to have produced an X-ray flux of X28. Holographic and visual observations indicate significant activity continued on the far side of the Sun.

LCROSS Viewer's Guide - NASA News


Just imagine. A spaceship plunges out of the night sky, hits the ground and explodes. A plume of de bris billows back into the heavens, lead ing your eye to a second ship in hot pursuit. Four minutes later, that one hits the ground, too. It's raining spaceships!

Put on your hard hat and get ready for action, because on Friday, Oct. 9th, what you just imagined is really going to happen--and you can have a front row seat.

Right: A computer visualization of LCROSS hitting the Moon on Oct. 9th. Credit: NASA/Ames

The impact site is crater Cabeus near the Moon's south pole. NASA is guiding the Lunar Crater Observation and Sensing Satellite ("LCROSS" for short) and its Centaur booster rocket into the crater's floor for a spectacular double-impact designed to "unearth" signs of lunar water.

There are two ways to watch the show.

First, turn on NASA TV. The space agency will broadcast the action live from the Moon, with coverage beginning Friday morning at 3:15 am PDT (10:15 UT). The first hour or so, pre-impact, will offer expert commentary, status reports from mission control, camera views from the spacecraft, and telemetry-based animations.

The actual impacts commence at 4:30 am PDT (11:30 UT). The Centaur rocket will strike first, transforming 2200 kg of mass and 10 billion joules of kinetic energy into a blinding flash of heat and light. Researchers expect the impact to throw up a plume of debris as high as 10 km.

Close behind, the LCROSS mothership will photograph the collision for NASA TV and then fly right through the debris plume. Onboard spectrometers will analyze the sunlit plume for signs of water (H2O), water fragments (OH), salts, clays, hydrated minerals and assorted organic molecules.

"If there's water there, or anything else interesting, we'll find it," says Tony Colaprete of NASA Ames, the mission's principal investigator.

Above: The lunar south pole as it will appear on the night of impact. Photo Credit - NMSU / MSFC Tortugas Observatory. [larger image]

Next comes the mothership's own plunge. Four minutes after the Centaur "lands," the 700 kg LCROSS satellite will strike nearby, sending another, smaller debris plume over the rim of Cabeus.

The Hubble Space Telescope, the Lunar Reconnaissance Orbiter (LRO), and hundreds of telescopes great and small on Earth will scrutinize the two plumes, looking for signs of water and the unexpected.

And that brings us to the second way to see the show: Grab your telescope.

"We expect the debris plumes to be visible through mid-sized backyard telescopes—10 inches and larger," says Brian Day of NASA/Ames. Day is an amateur astronomer and the Education and Public Outreach Lead for LCROSS. "The initial explosions will probably be hidden behind crater walls, but the plumes will rise high enough above the crater's rim to be seen from Earth."

The Pacific Ocean and western parts of North America are favored with darkness and a good view of the Moon at the time of impact. Hawaii is the best place to be, with Pacific coast states of the USA a close second. Any place west of the Mississippi River, however, is a potential observing site.

Right: The side of Earth facing the Moon at the time of impact. [larger image] [observing tips]

When the plumes emerge from Cabeus, they will be illuminated by sunshine streaming over the polar terrain. The crater itself will be in the dark, however, permanently shadowed by its own walls. "That's good," says Day. "The crater's shadows will provide a dark backdrop for viewing the sunlit plumes."

In an earlier stage of mission planning, scientists hoped to strike a crater closer to the Moon's limb so that the plumes would billow out against the dark night sky, providing maximum contrast for observers on Earth. However, recent data from NASA's Lunar Reconnaissance Orbiter, Japan's Kaguya spacecraft and India's Chandrayaan-1 probe altered those plans.

"We've just learned that Cabeus may contain relatively-rich deposits of hydrogen and/or frozen water," says Colaprete. "Cabeus is not as close to the lunar limb as we would have liked, but it seems to offer us the best chance of hitting H2O."

The LCROSS team hopes many people—amateurs and professionals alike—will observe and photograph the plumes. "The more eyes the better," says Day. "Remember, we've never done this before. We're not 100% sure what will happen, and big surprises are possible."

Right: Click on the image to find a public viewing event near your hometown. [more]

Veteran amateur astronomer Kurt Fisher has prepared a 13 MB slideshow to help fellow amateurs locate and witness the plumes: download it . There is also an online LCROSS observer's group where novices can read introductory articles and chat with other observers.

"This is a wonderful opportunity for citizen scientists to join NASA in the process of discovery," says Day, who urges observers to submit their images to the LCROSS Citizen Science Site. "It's a great adventure, and anyone can participate."

Imagine that.

Author: Dr. Tony Phillips | Credit: Science@NASA

more information
NASA TV -- watch the impacts on line!

LCROSS Photographed by Backyard Astronomers -- (Science@NASA)

School Kids Track LCROSS -- (Science@NASA)

NASA's Impact Party Toolkit

LCROSS Home Page -- (NASA/HQ)

LCROSS Mission Page -- (NASA/Ames)

Microwaving Water from Moondust - NASA News

"No magic--" says Ed Ethridge of NASA's Marshall Space Flight Center "-- just microwaves. We're showing how microwaves can extract water from moondust by heating it from the inside out."

see captionThe recent discovery of water on the Moon's surface has inspired researchers like Ethridge to rev up the development of technologies to capture it. Some of them believe the small amounts of frozen water mixed in lunar topsoil are just the tip of the iceberg.1 If so, Ethridge has figured out a way to retrieve it.

Right: Apollo 12 astronaut Alan Bean holds up a thermos full of moondust. Could this be transformed into a thermos of moonwater? NASA scientists are working on it. [larger image]

"We believe we can use microwave heating to cause the water ice in a lunar permafrost layer to sublimate – that is, turn into water vapor. The water vapor can be collected and then condensed into liquid water."

"Best of all, microwave extraction can be done on the spot. And it requires no excavation -- no heavy equipment for drilling into the hard-frozen lunar surface."

He calls his first mining experiment the "Moon in a bottle."

"We filled a bottle with simulated lunar permafrost [fake moondust containing water ice] and heated it in a microwave oven. The microwaves heated the simulant enough to extract water, even though the soil was as cold as it would be on the Moon."

At least 95 percent of the water added to the simulant was extracted (vaporized out of the soil) with 2 minutes of microwaving.

"And we were able to capture 99 percent of the vaporized water in our cold trap," says collaborator Bill Kaukler of the University of Alabama-Huntsville. "It works."

see caption

Above: Ed Ethridge's experimental setup at the Marshall Space Flight Center in Huntsville, Alabama. [larger image]

Then Ethridge and his team moved beyond the oven to beaming microwaves into the simulant – the way it would have to be done on the Moon. The beamed microwaves were absorbed into the soil and heated it sufficiently to extract water.

"This was an important demonstration. We had to make sure the microwaves wouldn't reflect off the surface," Ethridge explains. "It worked beautifully."

What's next?

"We've asked for some genuine soil from the Apollo missions," says Ethridge. "We want to test the real thing and calculate how fast the water vapor will come out. That's an important piece of information."

see captionRight: Click on the image to launch a 10 hour 3D animation showing how a 1KW microwave source entering from the top produces heating in a cubic meter simulated lunar soil. Colored bands represent locations of constant temperature. Credit: Ed Ethridge/NASA/MSFC [movie]

"There are other things we need to know, like how much ice is at the poles, how deep it is, where it is -- is it only in the craters or is it everywhere?" This Friday morning, Oct. 9th, LCROSS (the Lunar Crater Observation and Sensing Satellite) could answer some of the questions about moonwater when it plunges into crater Cabeus at the lunar south pole to unearth signs of H2O.

If ample water ice does exist on the Moon, how would lunar residents collect it?

"They'd have to beam microwaves into the soil and collect the water vapor in a cold trap," he explains. "We want to build a prototype water prospecting experiment to demonstrate the technique we’d like to see used in a lunar water mining facility."

He stops talking, looks up, and smiles. "I'd be willing to go up and set up the first Lunar Water Works -- if they'd let me."

Author: Dauna Coulter | Editor: Dr. Tony Phillips | Credit: Science@NASA

footnotes and credits
Footnote: 1Several days ago, NASA announced that the Moon Mineralogy Mapper, or M3, an instrument aboard the Indian Space Research Organization's Chandrayaan-1 spacecraft, discovered water molecules in the polar regions of the Moon. NASA's Cassini spacecraft and NASA's Epoxi spacecraft confirmed the find. Ethridge says: "The data [from the three aforementioned spacecraft] dealt with water detected from the top 1 or 2 mm of soil from regions like the Apollo sites, which are known to be "depleted" of any water (i.e., water produced from solar wind protons). But their data also shows much higher signals for water from the polar regions. The best locations for water ice are permanently shadowed craters near the poles. The water at the poles may be underneath a 1 cm depleted layer that overlies a higher concentration of water down to a meter deep. A few years ago, Lunar Prospector and Clementine produced data for hydrogen that translates to average concentrations estimated to be from 1 to 4.6 % water over large areas at the poles. Assuming an average 2 percent concentration, that translates to maybe 40 pounds -- about 5 gallons -- of water in a cubic meter of moon soil. (2 percent of a 1 ton is 40 pounds. A cubic meter of lunar soil is approximately 1 ton.)"

Credits: Dr. William Kaukler of the University of Alabama-Huntsville was instrumental in the experimental and hardware setups for these experiments. Frank Hepburn of Marshall led the dielectric property measurements. Southern Research Institute is doing some measurements for team on the gas permeability of compacted lunar soil.