Solar System

A probe that plummeted into Jupiter's atmosphere late in 1995 found more than twice the concentration of volatile elements, such as argon and nitrogen, than was expected, raising questions about standard theories of how the planets formed.The results, which a team of scientists led by Dr. Tobias Owen of the University of Hawaii is reporting in today's issue of Nature, suggest that at least some of the rocky, icy bits of dust and ice that crashed together to form Jupiter -- comet-like bodies called planetesimals -- must have originated under cooler conditions than prevail in the region of the solar system where the planet orbits now.Otherwise the planetesimals would not have been cold enough to trap the volatile gases, which would have been dispersed among the other tenuous matter in interplanetary space.

PUPILS AT MOUNT Airy Elementary had an opportunity to show off their talents at the school's Science Fair last month.Co-chairs Valerie Gilman and Dana Buswell and hostess Tammy Lyons helped the children find tables to set up their displays and answered questions.Projects included everything from hands-on demonstrations with static electricity to displays of animals and plants, human anatomy/physiology and techniques for treating water.Those attending the event April 21 also had the opportunity to throw water balloons outside as part of one pupil's project on distance and kinetics.

AUSTIN, Texas -- In a stunning run of discoveries over the past three years, astronomers have observed 17 nearby stars that appear to be orbited by planets more or less the size of Jupiter.The most recent detection of a planet around a star other than the Sun was described here yesterday.But while astronomers continue the search for more such objects, they have now seen enough to be puzzled by an emerging pattern: None of these extrasolar planetary systems seems to resemble the Sun's family of planets.

ONCE the dream of interplanetary romantics, the idea of traveling hundreds of millions of miles to Saturn by powering a spacecraft with a compact nuclear generator is well on its way to becoming a reality. But NASA's Cassini spacecraft's voyage has generated much controversy.Even before it thundered off the launch pad at Cape Canaveral, Fla., 19 months ago, anti-nuclear groups had protested NASA's plutonium-powered spacecraft, exploiting public fears about radiation.Now such groups are planning demonstrations timed to coincide with Cassini's orbital loop, when it flies within 800 miles of the Earth in mid-August.

"Journey Beyond Sele'ne': Remarkable Expeditions to the Ends of the Solar System," by Jeffrey Kluger. Simon & Schuster. 296 pages. $26.Thirty years ago this month, on July 20, 1969, millions of Americans watched, transfixed, as Astronaut Neil Armstrong hopped off a ladder and onto the face of the moon. Immediately, the nation annointed the men of Apollo 11 heroes, their lunar landing the fulfillment of an American dream.Lost in the hoopla that has always enveloped the manned missions to space are the stunning achievements of the unmanned rockets dispatched to the deepest reaches of the solar system, missions like Voyager, Galileo and Sojourner.

CancerOur sun is now in a constellation of stars called Cancer. Cancer is the Latin word for crab. But what does that have to do with the disease that has the same name?Cancer tumors sometimes have tangles of veins around them. Ancient doctors thought they looked like the tangled legs of a crab and named the disease cancer.Game Show of LifeCrabs have the same number of legs as:A - insectsB - spidersC - Barbra Streisand times 4D - 2 cowsE - the RockettesAnswer: Crabs look a lot like spiders that can live underwater.

A university sophomore in England, corresponding by e-mail, volunteered advice to the two American astronomers with a knack for finding planets around stars beyond our solar system: Focus their planet search on 30 overlooked stars and they might HTC make further discoveries.The astronomers agreed to look with the powerful Keck Observatory telescope in Hawaii. Sure enough, orbiting one of the student's candidate stars, 154 light-years away in the constellation Cygnus and designated HD187123, is a planet the size of Jupiter, the largest planet in the solar system.

SAN FRANCISCO -- The world's champion planet-finders have discovered another new world, one tantalizingly close to Earth's doorstep.Two San Francisco State University astronomers and two of their colleagues found the planet orbiting a star called Gliese 876, 15 light-years away. It is far closer than any previously known planet outside Earth's solar system.The discovery of an extrasolar world so close to our own, and orbiting such a low-mass star, implies the galaxy is even more packed with these planets than previously believed, said lead researcher Geoffrey Marcy of San Francisco State.

"Other Worlds: The Search for Life in the Universe," by Michael D. Lemonick. Simon & Schuster. 352 pages. $25. Are we alone in the universe? As of now, the answer is unequivocal. There are no aliens orbiting the earth or living among us. E. T. has not phoned in from some other solar system. There is no evidence that any sort of life exists anywhere but on our earth.Yet this answer comes with a crucial qualification: We've never actually seen any of the places outside our solar system where life might be found.

WASHINGTON -- The search for life in outer space got a boost yesterday as astronomers announced the discovery of a newborn solar system -- 200 light years away in our own Milky Way galaxy -- that looks a lot like a snapshot of our own solar system in its infancy."

Scientists say they may have to re-think some of their best theories about the origins and evolution of the planet Mercury as new data from the Sept. 29 flyby of the planet by the Maryland-built Messenger spacecraft continue to surprise. In their latest discussion of the mission's scientific findings, scientists said Tuesday they have found evidence that volcanic activity, including explosive eruptions, continued until unexpectedly recent times. The evidence appears in photos of an unnamed volcanic crater, 180 miles wide with a double ring around it. Its interior is surprisingly smooth and free of subsequent meteor impact craters, suggesting there were lava flows into the center as recently as a billion years ago. Scientists had thought Mercury's vulcanism, like that on Earth's moon, was among the first in the solar system to cease, at least 3 billion years ago. But "if the basin is young and the interior is even younger ... that may not be the case," said Brett Denevi, an imaging team member from Arizona State University in Tempe.

Jane Buxton Brown of Lakehurst wonders about the solar system: "Will you tell me how planets got into their orbits originally, and why they stay in them?" The planets condensed and grew amid cooling and collisions of gas and dust in the rotating solar "nebula" that circled the infant sun. Momentum will keep them circling unless something - the pull of a passing star, perhaps - kicks them out.

Meteors that smashed into the planet Mercury 3.9 billion years ago are giving scientists a glimpse deep into the tiny planet's interior and providing clues to how it has evolved in the eons since. The 430-mile-wide Rembrandt impact basin, first seen by NASA's Maryland-built Messenger spacecraft during two flybys last year, preserves cracks created during ancient upheavals from beneath the basin, as well as ridges formed like wrinkles as the planet cooled and shrank. "This is really exciting, because this pattern of tectonic land forms is different than anything we see anywhere in the solar system," said Thomas Watters, a scientist with the Smithsonian Institution in Washington who is part of the Messenger team.

The heavens are aligning to give Marylanders a rare look at a naked-eye comet as Lulin swings by en route to what could be a million-year exile in the far reaches of the solar system. Comet Lulin is the first comet visible from Maryland with the naked eye since Comet Holmes appeared in October and November 2007. You can see it already, but the view will be even better when it passes within 38 million miles of Earth on Monday evening, its closest approach since rounding the sun in January.

It was billed as a debate over the 2006 decision by the International Astronomical Union that kicked Pluto out of the family of planets, leaving just eight. But in the end, after a jocular and noisy tussle before scientists and educators gathered at the Johns Hopkins University's Applied Physics Laboratory, both debaters agreed that the IAU's definition only muddied the waters, and that more time is needed for science to sort out the increasingly complex range of objects circling our sun and other stars.

Physicist Rob Decker is obsessed with a region of space that has an ominous name: the termination shock. It's out there, at the very edge of the solar system, 90 times as far away as Earth is from the sun. It is the region where solar wind comes to a halt. There you will find huge, constant collisions as solar wind - the waves of hydrogen and helium plasma that shoot out from the sun at 1 million mph - crashes into a dense haze of charged particles flowing through interstellar space. Decker and his team at the Johns Hopkins Applied Physics Lab in Laurel used an instrument aboard the venerable Voyager 2 spacecraft this month to give astronomers the first detailed look at that smashup - in a region long shrouded in scientific mystery.

LAUREL -- When NASA's tiny Messenger spacecraft emerged from behind the planet Mercury yesterday afternoon, its radio beacon flashed across the solar system, and 107 million miles away, applause broke out in Maryland. The Maryland-built probe had just skimmed within 124 miles of the planet's surface, programmed to snap hundreds of photographs of a never-before-seen side of the sun's nearest neighbor. It was humanity's first close-up look at Mercury in almost 33 years. "Messenger is spectacular," said Alan Stern, NASA's associate administrator for science, who was in the control room near Laurel for the historic flyby.

It's probably just a coincidence that astronomers announced the discovery of an important new planet located outside our solar system this week, but I already was feeling as if I had been transported to some parallel world. How else do you explain the amazing groundswell of public support for Ravens backup quarterback Kyle Boller, who was considered the poster boy for all that was wrong with the team a couple of years ago? Let's take a look at the latest polling data and see whether we can put this situation into proper perspective: Recent political opinion surveys show President Bush with a 34 percent approval rating and Congress even lower at 22 percent, while Boller was the choice of 88 percent of respondents to a baltimoresun.

This is one task the political science textbooks obviously didn't address: What do you do when the dictator you deposed and imprisoned comes up on his release date? The answer, in regard to Manuel Noriega, tells as much about the process of nation-building in Latin America as it does international justice. The fact that Panama is not clamoring to bring Mr. Noriega back suggests Panamanian democracy, almost 20 years after the U.S. invasion and ouster of Mr. Noriega, remains shaky. If Panamanian institutions were strong and formidable, Mr. Noriega would be going home to face justice, and Panama would be ready to face up to its past.

Just after midnight Wednesday, a Maryland-built spacecraft bound for distant Pluto will soar past a key milepost in its nine-year voyage -- giant Jupiter and its turbulent system of moons and rings. It's not the first visit to Jupiter by a robotic mission from Earth. Six other spacecraft have passed by, and one, Galileo, orbited there for eight years. But scientists say their $700 million New Horizons craft will give them a new perspective on the Jovian system and on secrets that were inaccessible to prior missions.