NASA Selects Two Planet Finding Concepts

Image credit: NASA

NASA has selected two new concepts to advance the search for extrasolar planets; one of the technologies will eventually be selected for the Terrestrial Planet Finder mission. The first choice involves the use of an Infrared Interferometer, where multiple spacecraft will simulate a much larger observatory and search for the infrared signature of a planet around a distant star. The other concept is a Visible Light Coronagraph; a telescope 4 times as large and 10 times as powerful as Hubble, capable of imaging distant planets directly. NASA will choose one path in 2005-2006.

As part of its quest to find Earth-sized planets around stars and look for telltale chemical signatures of life, NASA has chosen two mission architecture concepts for further study and technology development.

The two architectures are being explored for the Terrestrial Planet Finder mission. Each would use a different means to achieve the same goal ? to block the light from a parent star in order to see its much smaller, dimmer planets. That technology challenge has been likened to finding a firefly near the beam of a brilliant searchlight from far away. Additional goals of the mission would include characterizing the surfaces and atmospheres of newfound planets, and looking for the chemical signatures of life.

The two candidate architectures are:

— Infrared Interferometer: Multiple small telescopes on a fixed structure or on separated spacecraft flying in precision formation would simulate a much larger, very powerful telescope. The interferometer would utilize a technique called nulling to reduce the starlight by a factor of one million, thus enabling the detection of the very dim infrared emission from the planets.

— Visible Light Coronagraph: A large optical telescope, with a mirror three to four times bigger and at least 10 times more precise than the Hubble Space Telescope, would collect starlight and the very dim reflected light from the planets. The telescope would have special optics to reduce the starlight by a factor of one billion, thus enabling astronomers to detect the faint planets.

The Terrestrial Planet Finder project at NASA?s Jet Propulsion Laboratory, Pasadena, Calif., selected the two candidates based on results from four industrial-academic teams that conducted a 2-1/2 year study of more than 60 possible designs. The two architectures were determined to be sufficiently realistic to warrant further study and technological development in support of a launch of Terrestrial Planet Finder by the middle of the next decade.

NASA and JPL will issue calls for proposals seeking input on the development and demonstration of technologies to implement the two architectures, and on scientific research relevant to planet finding. It is anticipated that one of the two architectures will be selected in 2005 or 2006 to be implemented for the mission, which may include international collaboration.

Terrestrial Planet Finder is part of NASA?s Origins Program, a series of missions to study the formation of galaxies, stars and planets, and to search for life. The program seeks to answers the questions: Where did we come from? Are we alone?

More information on the Terrestrial Planet Finder is available at .

More information on the Origins Program is available at . Additional information on JPL?s planet-finding missions is available at .

JPL manages the Terrestrial Planet Finder mission and the Origins Program for NASA’s Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena.

Original Source: NASA News Release

New Planetary Show on Monday

Image credit: NASA

The moon and five planets will appear close together in the night sky on Monday evening forming a rarely seen planetary conjunction. Look to the West, just after sunset. The planet Venus will be the brightest object in the sky, with Mars and Saturn below, and Jupiter above – Mercury will be visible just above the horizon, much dimmer than the rest. This will be the tightest conjunction of the planets in 40 years.

The Moon will join five visible planets to perform a seldom-seen celestial show on the evening of May 13.

To see the conjunction of the planets and moon, look in the western sky above the horizon just after sunset. Look for Venus, the brightest star in the group. Red Mars will be right below, and Jupiter, which appears white, will be topmost. Mercury is closest to the horizon, and Saturn is just below Mars.

“You’ll see just a sliver of the Moon, because it will be one day past new,” said Dr. E.M. Standish, an astronomer, also of JPL. “This will be the tightest conjunction for almost 40 years.”

A five-planet conjunction isn’t new; astronomers have been recording the phenomenon for over 3,500 years. Dr. Kevin Yau, an astronomer at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., has studied ancient Chinese astronomy texts to find out more about the conjunction.

“The Han Dynasty came to power in 605 BC,” Yau said. “One year later astronomers saw a five-planet conjunction gathered in the constellation Dongjing – what we would call Gemini.” This led to the ancient Chinese belief that the conjunction was an omen of change, but the alignment really has no effect on Earth or Earthlings.

Based upon good observing circumstances, 40 five-planet conjunction events may [vcm2]have been seen between the years 2000 BC and AD 2000. The next time these bodies will be grouped so closely together will be in September 2040.

“This alignment is a great opportunity to see the planets, since they are so easy to find in the sky,” he said.

As part of the imperial establishment in ancient China, an astronomical observatory was usually built inside the capital city of the time. Trained astronomers were appointed to keep a diligent watch of the sky day and night. The Chinese constellations have names that represent palaces and gardens, generals and ministers.

“Today, we are grateful that such detailed observational records were kept,” Yau said. “Our modern astronomical database goes back about five hundred years, which is relatively short in terms of astronomical timescales.” Astronomers often need to access data covering a longer time span in order to prove or disprove their theories such as the effect of the 11-year solar cycle on the Earth’s climate change, or predictions of when a comet will be visible from Earth.

JPL is managed for NASA by the California Institute of Technology in Pasadena.

Original Source: NASA/JPL News Release

Baikonur Cosmodrome Roof Collapses

The roof of an 80-metre hanger at the Baikonur cosmodrome in Kazakhstan collapsed on Sunday trapping eight workers under the debris. Russian officials believe it’s unlikely any of the workers survived the fall, and have prevented anyone from approaching the hanger for fear the unsteady walls could cave in as well. The collapsed hanger was built in the late 60s for the Soviet space program, and was later used to house a Buran space shuttle.

Does Whatever a Spider Can

My wife and I went to see Spider-Man on Sunday, and so I thought I’d celebrate with a Hubble image of the Tarantula nebula (trust me, when you’ve got a six-month old, you celebrate the chance to see a movie).

To make this your computer screen’s background, click the image that matches your screen’s resolution, right-click “Set as Background”.

1024×768 (168K) – 800×600 (110K) – 640×480 (77K)

On a completely unrelated note, lots of you have a computer virus. I know this because I’m probably receiving hundreds of viruses a day from various readers. I can’t inform you individually because the virus disguises who actually sent it. Here’s a free virus scanner that I like.

Fraser Cain
Publisher, Universe Today

Slower Spinning Stars Puzzle Astronomers

Image credit: NASA
NASA astronomers are studying a strange set of stars that spin much slower than expected. Normally, young stars spin quickly as its gravity pulls gas and dust into the centre, but a certain percentage of stars don’t – and astronomers don’t know why. There are several theories, but the most intriguing one is that planets have already formed around the star and are stealing momentum away from the parent star. NASA’s Origins mission, due for launch next year will help detect planet-forming disks around these young stars.

They don’t know why, but scientists say some adolescent stars rebel against the norm by spinning more slowly than their peers.

Normally, a young star gets smaller as its gravity pulls gas and dust in toward its center; the smaller the star gets, the faster it spins. But a scientist with NASA’s Jet Propulsion Laboratory, Pasadena, Calif., and her colleagues have found that a significant percentage of adolescent stars do not spin faster as they shrink.

“A young, shrinking star should behave like a skater who pulls in her arms to make herself smaller and spin faster,” said Dr. Luisa Rebull, a staff scientist at JPL and the California Institute of Technology in Pasadena, which manages JPL for NASA. “We don’t know why some stars act differently, but we’d sure like to find out.”

Rebull offers four possible reasons for the odd behavior:

1 — It is simply a quirk of the process by which the stars formed.

2 — The stellar winds are carrying away the angular momentum, or spin. This is like a skater who extends her arms away from her body to slow down.

3 — The magnetic field generated by the young stars locks their rotation to the slower rotation rate of the dust and gas disks around them, disks that might eventually form planetary systems.

4 — The stars have already formed planets from their disks. In our solar system, the largest planet, Jupiter, has the most angular momentum, or spin. Maybe other planetary systems are operating the same way, with large planets “stealing the momentum” from the parent star.

The fourth possibility intrigues scientists with NASA’s Origins Program, which will hunt for Earthlike planets that might harbor life. If orbiting planets cause this odd stellar behavior, scientists might detect them by looking for this trait. Rebull is a scientist on a new Origins mission, the Space Infrared Telescope Facility. The mission will launch early next year on a mission which, as one of its many goals, will look for planet-forming disks around other stars. A subsequent Origins mission, the Space Interferometry Mission, will look for planets around young stars to investigate the planet hypothesis directly.

For this current research, Rebull and her team studied more than 9,000 stars in the Orion Nebula and the Christmas Tree Cluster, also known as NGC 2264. They observed about 500 stars with large spots. The spots are like Sunspots, but much bigger, covering a large portion of the star’s surface. As the stars rotate, the spots come into and out of view, causing tiny changes in the total light we see from the star. Some of these stars appear redder than expected. That might indicate they have dust disks around them, Rebull said, which could interact with the star to slow its rotation. This might support the third possible explanation.

The researchers used the .76-meter (30-inch) telescope at the McDonald Observatory in western Texas. They also incorporated data from the National Optical Astronomy Observatory, Tucson, Ariz. The research paper, which Rebull co-authored with Drs. Sidney Wolff and Steven Strom of the National Optical Astronomy Observatory, and Russell Makidon of the Space Telescope Science Institute, Baltimore, Md., will appear in the July 2002 issue of the Astronomical Journal.

Original Source: NASA/JPL News Release

SPOT 5 Launched on Board Ariane Rocket

An Ariane 4 rocket blasted off from Kourou, French Guiana Saturday morning at 0131 GMT (9:31 pm EDT Friday), carrying a French-built SPOT 5 remote sensing satellite. The spacecraft separated from the booster 19 minutes after launch and was placed into an 810-km Sun-synchronous orbit. The satellite will provide high-resolution images of the Earth’s surface at a resolution of 2.5 metres. This was Arianespace’s 200th rocket launch.

Delta Launches Aqua Satellite

Image credit: NASA

NASA’s newest Earth observation satellite launched Saturday aboard a Boeing Delta II rocket. Called Aqua, the satellite will gather data about global precipitation, evaporation and the cycling of water to help scientists understand if there’s any acceleration of the Earth’s water cycle and due to changing climate. The infrared sounder on board will measure the Earth’s atmosphere and help improve weather prediction.

NASA’s latest Earth observing satellite, Aqua, carrying the NASA Jet Propulsion Laboratory-managed Atmospheric Infrared Sounder instrument, successfully launched this morning at 2:55 a.m. Pacific Time. Aqua is dedicated to advancing our understanding of Earth’s water cycle and our environment. Launching the Aqua spacecraft marks a major milestone in support of NASA’s mission to help us better understand and protect our planet.

The Aqua spacecraft lifted off from the Western Test Range of Vandenberg Air Force Base, Calif., aboard a Delta II rocket. Spacecraft separation occurred at 3:54 a.m. Pacific Time, inserting Aqua into a 705-kilometer (438-mile) orbit.

“The Aqua project has truly been a team effort and we are very excited this morning,” said Aqua project manager Phil Sabelhaus at NASA’s Goddard Space Flight Center, Greenbelt, Md.

The primary goal of Aqua, as the name implies, is to gather information about water in Earth’s system. Equipped with six state-of-the-art instruments, Aqua will collect data on global precipitation, evaporation and the cycling of water. This information will help scientists all over the world to better understand Earth’s water cycle and determine if the water cycle is accelerating as a result of climate change.

JPL’s Atmospheric Infrared Sounder will measure Earth’s atmosphere and surface, allowing scientists to improve weather prediction and observe changes in Earth’s climate.

Aqua is the latest in a series of Earth Observing System spacecraft, following the Terra satellite launched in December 1999. Aqua will cross the equator daily at 1:30 p.m. as it heads north. The early afternoon observation time contrasts with the Terra satellite, which crosses the equator between 10:30 and 10:45 a.m. daily. Aqua’s afternoon observations, combined with Terra’s morning observations, will provide important insights into the daily cycling of key scientific parameters such as precipitation and ocean circulation.

Aqua is a joint project among the United States, Japan and Brazil. The United States provided the spacecraft and four of the six scientific instruments. In addition to the JPL-provided Atmospheric Infrared Sounder, the other U.S. instruments include the Moderate Resolution Imaging Spectroradiometer and the Advanced Microwave Sounding Unit, both provided by the Goddard center, and the Clouds and the Earth’s Radiant Energy System, provided by NASA’s Langley Research Center, Hampton, Va.

Japan’s National Space Development Agency provided the Advanced Microwave Scanning Radiometer, while the Instituto Nacional de Pesquisas Espaciais (the Brazilian Institute for Space Research) provided the Humidity Sounder for Brazil.

Aqua is part of NASA’s Earth Science Enterprise, a long-term research effort dedicated to understanding and protecting our home planet. Through the study of Earth, NASA will help to provide sound science to policy and economic decision makers so as to better life here, while developing the technologies needed to explore the universe and search for life beyond our home planet.

Original Source: NASA/JPL News Release

Shuttleworth Returns to Earth

South African space tourist Mark Shuttleworth returned to Earth safely on Sunday after spending 10-days in space, including a visit to the International Space Station. Shuttleworth, cosmonaut Yuri Gidzenko and Italian astronaut Roberto Vittori stepped from their Soyuz capsule near the Kazakhstan town of Arkalyk, and were greeted fondly by locals, friends and family. To remember his trip to space, Shuttleworth bought the Soyuz capsule and his flight suit.

IMAX Space Station 3D

If you’ve got an IMAX theatre nearby, you might want to check out their latest offering: IMAX Space Station 3D. They lugged one of those giant IMAX cameras up to the International Space Station and captured some of the life on 65mm film – in 3D! If you want more information, check out the special website at: IMAX Space Station

I haven’t seen the movie yet (maybe Chloe wants to go), but it sounds pretty cool. Let me know if you’ve seen it and have an opinion.

Fraser Cain
Publisher, Universe Today

Taking the Temperature of a Hurricane’s Eye

Image credit: NASA

When Hurricane Erin was beating up the North Atlantic last year, NASA researchers decided to take its temperature. Using a special aircraft, researchers dropped eight sensors into the area round the storm’s eye, a place that contains the most powerful winds and warmest temperatures. Using this data, they were able to create a three-dimensional image of the complete inner core.

Last year, NASA researchers took the temperature of the eye of Hurricane Erin to determine how a hurricane?s warm center fuels the strength of storms. The new data is helping scientists understand the inner workings of hurricanes at very high altitudes, and will improve future hurricane forecasts.

The researchers found that the warmest portion around a hurricane?s eye is approximately 3.5 miles high and that area in the eye corresponds with falling pressure, which is what causes the winds to spiral inward at destructive speeds.

During September 2001 while flying over the North Atlantic Ocean, scientists aboard NASA?s ER-2 aircraft dropped eight sensors into the area around Hurricane Erin?s eye, containing the strongest thunderstorms and winds, and warmest temperatures. Variations in temperatures within a hurricane provide clues about the storm?s intensity. For example, a warm center marked by a large temperature contrast compared to the rest of the hurricane is a sign of a strong storm.

The sensors measured temperature, air pressure and winds as they fell through the hurricane and transmitted their data back to the ER-2 aircraft. For the first time, the data allowed scientists to create a comprehensive 3-dimensional image of the complete inner core (including the eyewall and the eye) of a hurricane, giving scientists a better look at how heat from warm, rising air spreads out in the storm?s center. The warm, humid, rising air is the key to a hurricane?s power. This rising air draws in air from the surface to take its place, and creates winds.

?Scientists can obtain a detailed look at a hurricane?s heat engine (the warm temperatures that power a storm) by combining the aircraft data with that from satellites such as NASA?s Tropical Rainfall Measurement Mission,? said Jeff Halverson, a scientist from NASA?s Goddard Space Flight Center, Greenbelt, Md., and the University of Maryland Baltimore County.

?The data from the sensors and the satellite have given us a view of the eye?s warm air, the rain clouds that warm the air through condensation, and the spiraling surface winds which in turn create the rain clouds. We have assembled all this data in a three dimensional rendition of the hurricane which is akin to taking a detailed ?CAT scan? of the storm,? Halverson said.

?We found that this storm had a very warm eye, from the ocean to the top of the lower atmosphere at around 10 miles altitude,? said Halverson. The warmest part of Erin?s eye was almost 21 degrees (Fahrenheit) warmer than the surrounding air, a dramatic difference from the air around it. Above 7.5 miles high, the eye?s temperature dropped quickly to the same temperature as the air outside the eye.

The warming temperatures within the hurricane?s eye make the air lighter, so air pressure eases on the surface and falls. When air is cold, the air molecules are dense, and air is heavier. The falling pressure in the hurricane?s eye is what creates swirling destructive winds.

The experiment also discovered that strong rising air currents in Erin caused the tropopause (top of the lower atmosphere) to ?bubble up? or bend, south of the eye?s center. This is indicative of the strength of Hurricane Erin, which was a Category 3 storm at this time.

There are five categories in which hurricanes are classified, the fifth being the most devastating. Category 3 hurricanes, such as Erin have winds between 111-130 mph, and can bring a storm surge of water (wind driven water above tide level) between 9-12 feet to shorelines.

Halverson will be presenting these findings at the AMS Hurricane and Tropical Meteorology Conference in San Diego, Calif. on Tuesday, April 30, 2002 at 9:00 a.m. Pacific time in a session titled ?Thermal Structure of Hurricane Erin?s Core Using Dropsonde Data From 68,000 Feet and Comparison with AMSU Satellite Measurements.?

Original Source: NASA News Release