A NASA spacecraft sped past a small comet Thursday, beaming pictures back to Earth that gave scientists a rare close-up view of its center. Mission controllers burst into applause upon seeing images from the flyby that revealed a peanut-shaped comet belching jets of poisonous gases.
The close encounter occurred 13 million miles from Earth when the Deep Impact craft, hurtling through space, flew within 435 miles of comet Hartley 2. It's only the fifth time that a comet's core has been viewed up close.
Scientists are interested in comets because they're icy leftovers from the formation of the solar system about 4.5 billion years ago. Studying them could provide clues to how Earth and the planets formed and evolved.

Thursday's flyby is actually an encore mission for Deep Impact. It set off cosmic fireworks on July 4, 2005, when it fired a copper probe that crashed into comet Tempel 1. The high-speed collision spewed a cloud of debris into space, giving scientists their first peek of the interior.

After the $333 million comet-buster, NASA recycled Deep Impact for a new mission to visit another comet. It was supposed to target comet Boethin in 2008, but it was nowhere to be found. Scientists theorized the comet may have broken up into small pieces.

Deep Impact was then redirected to Hartley 2. Roughly 1 1/2 miles long, Hartley 2 is the smallest comet to be photographed up close. On its way there, the craft spent several months scanning a cluster of nearby stars with known planets circling them.

While its latest task lacks the Hollywood drama of the Tempel 1 crash, researchers still consider it an important mission. Unlike in 2005, viewers could not see Thursday's comet encounter in real time since the craft's antenna was not pointed at Earth as it flew past Hartley 2.

Since September, Deep Impact has been stalking Hartley 2 like a paparazzo, taking images every 5 minutes and gathering data. It's the first craft to visit two comets.

Deep Impact will observe Hartley 2 until Thanksgiving and then wait for further instructions from NASA. The space agency has not decided whether to reuse Deep Impact again. The craft does not have enough fuel on board to do another flyby.

The latest images add to scientists' cometary photo album, said astronomer David Jewitt of the University of California, Los Angeles, who had no role in the project.

Hartley 2 passed within 11 million miles of Earth on Oct. 20 — the closest it has been to our planet since its discovery in 1986.

British-born astronomer Malcolm Hartley, who discovered the comet, said he never imagined a spacecraft would get so close to his namesake find.

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Astronomers believe they've found the oldest thing they've ever seen in the universe: It's a galaxy far, far away from a time long, long ago.

Hidden in a Hubble Space Telescope photo released earlier this year is a small smudge of light that European astronomers now calculate is a galaxy from 13.1 billion years ago. That's a time when the universe was very young, just shy of 600 million years old. That would make it the earliest and most distant galaxy seen so far.

By now the galaxy is so ancient it probably doesn't exist in its earlier form and has already merged into bigger neighbors, said Matthew Lehnert of the Paris Observatory, lead author of the study published online Wednesday in the journal Nature.

"We're looking at the universe when it was a 20th of its current age," said California Institute of Technology astronomy professor Richard Ellis, who wasn't part of the discovery team. "In human terms, we're looking at a 4-year-old boy in the life span of an adult."

While Ellis finds the basis for the study "pretty good," there have been other claims about the age of distant space objects that have not held up to scrutiny. And some experts have questions about this one. But even the skeptics praised the study as important and interesting.

The European astronomers calculated the age after 16 hours of observations from a telescope in Chile that looked at light signatures of cooling hydrogen gas.

Earlier this year, astronomers had made a general estimate of 600 to 800 million years after the Big Bang for the most distant fuzzy points of light in the Hubble photograph, which was presented at an astronomy meeting back in January.

In the new study, researchers focused on a single galaxy in their analysis of hydrogen's light signature, further pinpointing the age. Garth Illingworth of the University of California, Santa Cruz, who was the scientist behind the Hubble image, said it provides confirmation for the age using a different method, something he called amazing "for such faint objects."

The new galaxy doesn't have a name — just a series of letters and numbers. So Lehnert said he and colleagues have called it "the high red-shift blob. "Because it takes so long for the light to travel such a vast time and distance, astronomers are seeing what the galaxy looked like 13.1 billion years ago at a time when it was quite young — maybe even as young as 100 million years old — Lehnert said. It has very little of the carbon or metal that we see in more mature stars and is full of young, blue massive stars, he said.

What's most interesting to astronomers is that this finding fits with theories about when the first stars and galaxies were born. This galaxy would have formed not too soon after them.

"We're looking almost to the edge, almost within 100 million years of seeing the very first objects," Ellis said. "One hundred million years to a human seems an awful long time, but in astronomical time periods, that's nothing compared to the life of the stars."

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