Year in Review
Many international science journals remembered 2003 as the year astronomers first precisely dated the beginning of the universe, or Big Bang, using the faint, microwave noise available from a remarkable satellite measurement. The end of the year brought a flurry of new missions important to astrobiology, including the first fly-through of a comet (Stardust) and the first opportunity for multiple martian landers to rove the red planet in nearly four decades. 2003 heralded the centennial of powered flight, along with fiftieth anniversaries for the discovery of DNA's double helix and the landmark laboratory synthesis of prebiotic soup ingredients.
Astrobiology Magazine reviews this year's events and anticipates what 2004 may offer.
|An alternative explanation for the early erosion that made river valleys is colossal energy releases from asteroid impacts.
Image Credit: Don Dixon
Computer simulations published which link some erosion and water features on Mars to rare asteroid strikes. If today's Mars shows remnants of ancient hot, wet conditions, the model predicts they were ephemeral: the planet would refreeze within a few decades or centuries after any of the 25 craters more than 100 kilometers in diameter visible today on Mars. Only after the collision of another asteroid, perhaps 10 to 20 million years later, would the warmth return.
New planet found eclipsing its own star and dimming the light that reaches earth. Analysis points to strange weather, where exotic storms rain down not water, but iron. In these transit searches, astronomers look for systems where, from our point of view, a planet passes directly in front of the parent star it is orbiting. The technique extends the stellar search field from 40 thousand current stellar candidates for planet discoveries to 100 million or more.
|The farthest known planet ever discovered is a strange world indeed. Whizzing around its star every 29 hours, it is shrouded in clouds made not of water droplets but of iron atoms. This is a world of iron rain.
Credit: David A. Aguilar, Harvard-Smithsonian Center for Astrophysics
Space shuttle Columbia tragedy.
Microwave measurements precisely date the Big Bang at 13.7 billion years ago, with a remarkable 1% error prediction
The light from a massive explosion 2 billion years ago just arrives on Earth, thus setting off a global flurry of robotic telescopes to track what turned out to be 100 times more intense than any previously studied supernova events. The event was dubbed a hypernova, since the optical brightness of this gamma ray burst was about 100 times more intense than anything ever seen before.
SETI@home classifies 150 most promising radio signals for revisiting, Arecibo Observatory
Mars has liquid core: Three years of radio tracking data from the Mars Global Surveyor spacecraft, suggest that Mars has not cooled to a completely solid iron core--rather its interior is made up of either a completely liquid iron core or a liquid outer core with a solid inner core.
Fiftieth anniversary of Watson-Crick discovery of DNA's double helix.
New planet found with the shortest year (orbital period, 28 hours) yet. The distance between the star and the planet is correspondingly small, only 3.5 million kilometers, and the star-facing side must be in excess of 2000 °C. The planet is literally evaporating.
A survey of some 1,000 stars reveals about 10 percent have planets, most of which are called gas giants and generally range in size from about the mass of Jupiter to 10 times that large. During the next 15 years or so, American and European scientists hope to launch more than half a dozen missions to search our corner of the Milky Way galaxy for terrestrial planets.
Fiftieth anniversary of primordial soup experiments to create building blocks of life from simple organic compounds and an electric spark. Stanley Miller and Harold Urey published a landmark two-page paper in Science magazine, considering if amino acids could be made from what was known about the early Earth's atmosphere
Japan's MUSES-C spacecraft, launched May 2003, is headed for asteroid 1998 SF36--the world's first mission to collect samples from the surface of an asteroid amd part of a four-year journey covering nearly 400 million miles. After its arrival in June 2005, the spacecraft will gather up to one gram of material from a variety of sites on the asteroid. The samples are expected to arrive back on Earth by June 2007.
European Space Agency successfully launched its first probe to another planet--Mars Express. Its comprehensive maps will feature 10 meter resolution, but some particularly interesting regions will get a close-up view to 2 meters [about the size of small car, as seen from orbit]. If pockets of water are found to a depth of 2 kilometers [1.2 miles], then theories of active hydrology on Mars will be borne out. The orbiter mission should last at least one Martian year (687 days).
|View of Mars Exploration Rover (MER) mission as landing airbag deploys above Martian surface. Credit: NASA/JPL MER
Mars rover, Spirit, began journey leading to an eventual three months of exploration on the martian surface. To help scientists determine whether there was ever enough water on Mars to sustain life, the motorized explorer will send back images of sediment and mineral deposits.
Mars rover, Opportunity, launches. Both the Mars Exploration Rovers, Opportunity and Spirit, will have panoramic cameras and much greater mobility than previous rovers to travel beyond where they initially come to rest.
Penn State astronomers combine Hubble images to find the oldest and most distant known planet. The globular cluster, known as M4, which hosts the new planet is located 5,600 light-years away, in the constellation Scorpius. This is the only planet that has been found in orbit around a binary star system.
Mars approaches Earth in what was the closest the planets have been in 73,000 years. At opposition Mars was as close as it had been since September 12, 57,537 B.C. or one-third closer than the average opposition.
|In the early morning of August 25, 2003, NASA launched the Space Infrared Telescope Facility (SIRTF) the fourth and final element in NASA's family of Great Observatories.
Credit: Ball Aerospace & Technologies Corp., 2003
NASA successfully launched its fourth and final element in the NASA family of Great Observatories--the infrared telescope called SIRTF, later renamed the Spitzer Telescope. During its 2.5-year mission, [although it could be extended to 5 years], the telescope's contributions to astrobiology will be in the spectroscopic study of carbon-bearing molecules and dust in the interstellar medium.
Unboilable bug found. The microbe "Strain 121" leads the hottest existence known to science--with the top temperature at which it survives: 121 degrees Celsius, or about 250 degrees Fahrenheit.
Galileo Jupiter Impact. After a 14-year journey of about 2.8 billion miles, the Galileo spacecraft crashed into the planet Jupiter in a planned event to culminate its mission without potentially contaminating the ice-covered Jovian moons that Galileo helped map in detail. The mission produced a string of discoveries about asteroids, a fragmented comet, Jupiter's atmosphere, Jupiter's magnetic environment, and especially about the geologic diversity of Jupiter's four largest moons.
SMART-1, Europe's first science spacecraft designed to orbit the Moon, launches successfully to demonstrate propulsion technologies like a solar-powered ion engine for efficient travel on long space missions. Using infrared detectors, SMART-1 will map lunar materials and look for water and carbon dioxide ice in permanently shadowed craters.
Five-year anniversary of Spaceguard, with the goal of finding and cataloging, by 2008, 90% of all near-Earth objects (NEOs) with diameters of 1 km or larger that could represent a collision risk to Earth. The total population of near-earth asteroids (NEAs) larger than 1 kilometer is about 1,100. In the last five years, telescopic search programs have found about 640 NEAs, so more than half of the estimate has been found already.
World's largest radio telescope reveals first evidence of liquid hydrocarbon lakes on the surface of Saturn's smog-covered moon, Titan. The surface of Titan--the second largest moon in the solar system-- is one of the last unstudied parcels of real estate in the solar system. The atmospheric pressure near its surface is 60 percent greater than on Earth at sea level and is thought to resemble that of early Earth-- but it is far colder and lacks liquid water.
|Scientists would like to know the origin of the atmospheric patches imaged on Saturn's moon, Titan, as imaged by Hubble. Image Credit: Hubble Space Telescope/UA Smith
Shortlist of 30 possibly habitable planets and stars compiled for target lists in NASA's Terrestrial Planet Finder (TPF), a space telescope project that will search for habitable planets after it is launched in about 10 years time. For concreteness, the star 37 Gem is given the honorary title of best candidate for harboring Earth-like planets.
The most alkaline-tolerant life known to date found at pHs up to 11 near south Chicago's caustic slag dumps. Thriving in extraodinary water more basic than ammonia floor-strippers, the bacteria exploits the hydrogen given off from the corrosion of metallic iron slag from the city's steel mills.
Despite evidence from two space probes in the 1990s, radar astronomers say they can find no signs of thick ice at the moon's poles. Because our moon is lifeless, it is one of the most appealing places to look for the preserved records of life elsewhere as it may be transferred by meteor impacts and enter lunar quarantine for billions of years.
Hurtling through the frigid expanse beyond the planets, NASA's aging spacecraft Voyager 1 has reached the edge of the Solar System, where it has encountered a massive shock wave. This phase begins the first direct measurements of our solar system's unexplored final frontier, the heliosheath.
|Red regions in the spiral arms represent infrared emissions from dustier parts of the galaxy where new stars are forming. Click for larger view. Credit: NASA/JPL-Caltech/S. Willner (Harvard-Smithsonian Center for Astrophysics).
The "Great Dying," a time of earth's greatest number of extinctions, is proposed to have been caused by the impact of a large meteor approximately 251 million years ago, when 70-90 percent of all terrestrial life became extinct.
The first images from the Space Infrared Telescope Facility (Spitzer) were made available, showing dazzling infrared views of distant stars and galaxies, and confirming the presence of organic molecules and other chemicals thought to be necessary for the origin of life in deep space.
Centennial of first powered flight, Wright Brothers, Kitty Hawk.
Mars Express successfully enters orbit around Mars. The landing probe, Beagle 2, does not transmit its initial signal, with current theories speculating a deep-crater may be obscuring its broadcast beacon.
Stardust to collect comet dust from fly-through encounter, January 2, as the first sample return mission to Earth since Apollo.
Spirit Mars Rover encounters Mars, January 3. Opportunity Mars Rover encounters Mars, January 26. Both are anticipated for at least three months of surface operations.
Europe launches Rosetta mission, to land a science probe on the surface of Comet Churyumov-Gerasimenko in 2014
Mercury orbiter, MESSENGER, to look for water-ice on the closest planet to the Sun
Cassini probe arrives at Saturn in July, with its descent spacecraft released to test Titan's atmosphere in December
Genesis to return pristine samples of solar wind to earth
Comet rendezvous, Deep Impact, to fire a bullet into comet P/Tempel 1 and study the ejecta and crater
Japanese Lunar-A, Lunar Mapping Orbiter and Penetrator, to fire two bullets 3 meters into the lunar soil near Apollo 12 and 14 sites
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