Comet Lovejoy plunged through the sun's corona at about 7 p.m. EST (midnight GMT on Dec. 16), coming within 87,000 miles (140,000 kilometers) of our star's surface. Temperatures in the corona can reach 2 million degrees Fahrenheit (1.1 million degrees Celsius), so most researchers expected the icy wanderer to be completely destroyed.
This movie was taken from the Solar Terrestrial Relations Observatory (STEREO). It provides the first space-based views of Comet Lovejoy on December 11. This comet moves in from the bottom right. (The moving red line is an artifact caused by the planet Mercury, which is off camera.)
Comet Lovejoy blazes toward the sun and its tail wiggles as it interacts with the solar wind. By the end of the day on December 15, 2011, the comet will graze some 75,000 miles above the sun's surface through the several million degree solar corona. Five different satellites, including the Solar Terrestrial Relations Observatory (STEREO), the Solar Heliospheric Observatory (SOHO), the Solar Dynamics Observatory (SDO), Hinode, and Proba, are trying to watch its final approach to the sun. This movie was recorded by STEREO using the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) instrument.
Another instrument watching the comet was the Solar Dynamics Observatory (SDO), which adjusted its cameras in order to watch the trajectory. Not only does this help with comet research—such as how big the comet is and what it's made of—but it may also help orient instruments on SDO. Since the scientists know where the comet is based on other spacecraft, they can finely determine the position of SDO's mirrors. This movie was taken from SDO on the evening of Dec. 15, 2011. It shows Comet Lovejoy moving in toward the sun. This video will loop 3 times to show the details. Credit: NASA/SDO
Comet Lovejoy survives its encounter with the sun. The comet is seen here exiting from behind the right side of the sun, after an hour of travel through its closest approach to the sun. By tracking how the comet interacts with the sun's atmosphere, the corona, and how material from the tail moves along the sun's magnetic field lines, solar scientists hope to learn more about the corona. This movie was filmed by the Solar Dynamics Observatory (SDO) in 171 Angstrom wavelength, which is typically shown in yellow. The video loops 3 times to show the footage. Credit: NASA/SDO
However, Lovejoy proved to be made of tough stuff. A video taken by NASA's Solar Dynamics Observatory (SDO) spacecraft (shown above) showed the icy object emerging from behind the sun and zipping back off into space.
SDO is one of many instruments that scientists—eager to record and study the comet's presumed demise—trained on Lovejoy as it streaked toward the sun.
"We have here an exceptionally rare opportunity to observe the complete vaporization of a relatively large comet, and we have approximately 18 instruments on five different satellites that are trying to do just that," Karl Battams, a scientist at the Naval Research Laboratory in Washington, D.C., wrote on the Sungrazing Comets website, before Lovejoy's closest solar approach.
Battams runs the website, which is devoted to comets discovered by two different spacecraft: NASA's Solar Terrestrial Relations Observatory (STEREO) and the Solar and Heliospheric Observatory (SOHO), which is operated jointly by NASA and the European Space Agency (ESA).
Battams greeted news of Lovejoy's improbable escape with surprise and delight.
"I expected a diffuse dust tail to survive (for several hours) before fading away but NOT any kind of nucleus!" he tweeted. "I've worked with sungrazers for 8yrs; today was the most amazing day I've ever had with them!"
Lovejoy has a core about 660 feet (200 meters) wide. It belongs to a class of comets known as Kreutz sungrazers, whose orbits bring them very close to the sun.
All Kreutz sungrazers are thought to be the remnants of a single giant comet that broke apart several centuries ago. They're named after the 19th-century German astronomer Heinrich Kreutz, who first showed that such comets are related.
Comets plunge into the sun on a regular basis, but they rarely give much advance notice of their suicidal intentions. That's why scientists were so excited about Lovejoy. Australian amateur astronomer Terry Lovejoy discovered the icy wanderer on Nov. 27, giving researchers plenty of time to map out their observation campaign.
And that campaign has been intense, involving five different spacecraft. In addition to SDO, SOHO, and STEREO, scientists planned to use Japan's Hinode satellite and ESA's Proba spacecraft to track Lovejoy's movements, Battams wrote.
NASA also created a website providing updates about the comet's pass through the corona, as well as images of the event beamed down by SDO. It can be found here: http://sdo.gsfc.nasa.gov/data/lovejoy.php
For his part, Terry Lovejoy said he was happy to have made a contribution, and he marveled a bit at all the attention the comet has been getting.
"It's been tremendous," Lovejoy told SPACE.com. "Apparently it's all over Facebook, and I don't use Facebook. But there's a lot of interest. I think a lot of people like the name—the Lovejoy name seems to strike a chord with people."
Lovejoy is quite large for a sungrazing comet, and experts expected it to die an impressive death. The website Spaceweather.com, for example, predicted Lovejoy would blaze as brightly as Jupiter or Venus in the sky as it neared the sun.
Battams also expected a good show, saying the comet might even be visible from the ground around sunset today in the Northern Hemisphere.
"I do think that it will put on a spectacular show for us and will be the brightest Kreutz-group comet that SOHO has ever observed," Battams wrote last week.
Though the early returns are still coming in, those forecasts appear to be on the money. Observations from various spacecraft do indeed show Lovejoy flaring up significantly as it neared our star.
Researchers will keep analyzing the images to better understand the comet's daring solar approach. And now, skywatchers apparently have another shot to catch a glimpse of the resilient Lovejoy on Friday morning (Dec. 16).
For observers in North America, the comet will rise approximately 5 to 10 minutes before dawn and will be situated to the upper right of the sun. If Lovejoy is still shining at least as brightly as Venus, it may be visible, experts say.
You could also try to spot Lovejoy after the sun comes up, if you're exceedingly careful. Block the rising sun behind a distant building and focus on the part of the sky 3 to 4 degrees above and to the right of the sun (your clenched fist held at arm's length is equal to rouughly 10 degrees). But a warning! Never point binoculars or a telescope at or near the sun, and never look directly at our star with the naked eye as serious eye damage can result.
Don't get your hopes up either. The comet may well be too faint to see, experts say.