Encore

By Jeffrey Winters|Friday, January 01, 1999
On February 20, 1962, John Glenn, flying in his capsule Friendship 7, became the first American to orbit Earth. On October 29, 1998, Glenn, now 77, returned to space for a nine-day mission aboard the shuttle Discovery. Readjusting to gravity upon his return to Earth was probably the most grueling part of Glenn's adventure. But he said he "slept like a log" on his first night back.

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Portraits of Stars Near and Far By Jeffrey Winters

SOHO, a space-based solar observatory that has helped revolutionize our understanding of the sun, began tumbling wildly in June, the victim of errant commands by ground controllers. It took engineers several months to rescue the spacecraft. Despite their efforts, some of SOHO's instruments were damaged by the months without full power. Though SOHO was back in place and up to full power by September, two of three gyroscopes used to orient the satellite now appear to be beyond repair, possibly limiting SOHO's useful lifetime. The image of the sun shown below was taken on June 24, just a few hours before the probe lost contact with ground control.

These SOHO images show the aftereffects of a flare erupting above the sun's surface. The shock wave created by the flare ripples across the surface like seismic waves from an earthquake--but this one contained 40,000 times the energy of the San Francisco earthquake of 1906. Much as geologists use seismic data to plumb Earth's depths, astronomers will use these data to better understand the sun's interior.

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The Not-So-Near Miss By Jeffrey Winters The newsletter of the Central Bureau for Astronomical Telegrams in Cambridge, Massachusetts, doesn't reach many people. But it contained a brief announcement in March that grabbed the world's attention, at least for a few days, inspiring headlines like ASTEROID ZEROES IN ON EARTH.

Astronomers at the Cambridge bureau reported that an asteroid discovered in December 1997 called 1997 xf11 might come within 30,000 miles of us in late October 2028. "The chance of an actual collision is small," the astronomers wrote, "but one is not entirely out of the question."

Even as the ink was drying on the headlines, however, astronomers across the country were scrambling to double-check the calculations. And as predictions of the asteroid's path were refined, it turned out that 1997 xf11 would miss us with 600,000 miles to spare--well outside the moon's orbit.

So what happened? Did someone forget to carry a 1 when making the initial calculation? Actually, nothing "went wrong." Instead this was an unusually public example of how astronomy works: observations lead to calculations that lead to new observations and refined calculations. "No scientific mistake was made," says Brian Marsden, whose March announcement touched off the controversy. "We simply reported that, based on the information that was available, this is what you get."

Marsden says he wanted to get the attention of astronomers who might inadvertently have photographed the asteroid in the past. (In fact, two groups had images from 1990 that helped pin down the asteroid's orbit.) And without this additional data, Marsden says, it would not have been possible to rule out a collision, if not in 2028, then sometime in the 2030s or 2040s.

The only problem was that much of the refining was done in the media spotlight, with developments and conflicts greatly exaggerated in the reporting. For example, while 1997 xf11 is not going to hit Earth in 2028, it often goes unreported that it will get closer to us than any currently known large asteroid in the next 80 years. And although in the aftermath of all this publicity NASA played up the doubling of its funding for the search for near-Earth asteroids, the $3 million commitment scarcely seems sufficient to some astronomers. James Scotti, who discovered 1997 xf11 while working on the University of Arizona's Project Spacewatch, says, "Our budget is about $1 million or $2 million a year. If everybody who went to see Armageddon and Deep Impact put a dime into a bin, we'd be able to complete our survey in no time flat."

If movies are any indication, death by asteroid would seem to have risen on the list of societal fears. Based on the number of ancient craters on Earth and on the moon, astronomers estimate that asteroids big enough to wipe out humanity probably hit Earth every few tens of millions of years. Of course, just because 1997 xf11 isn't going to smack Earth doesn't mean that another asteroid won't. Although there are believed to be some 2,000 objects a mile across or larger that intersect Earth's path, astronomers have charted the orbits of fewer than 200. Without a larger early-warning network of observers, Scotti warns, if we do have a date with destruction some time in the future, we may not find out until it's too late. --Jeffrey Winters

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Planets, Moons, a Supernova, and More By Jeffrey Winters

The difference between these two Hubble images of supernova 1987A -- the left one taken in 1994, the right one released in February -- is the bright knot in the newer image. This knot, some 100 billion miles wide, shows the first signs of an onrushing shock wave slamming into an encircling ring of gas. Astronomers expect the entire ring to light up over the next few years.

Mars Global Surveyor continued to send back images of the Martian surface, including some of the best evidence yet for terrain shaped by ancient torrents of water. This image shows channels in the wall and dark sediments on the floor of an unnamed crater in the southern hemisphere. Water probably carved these features as it seeped into the crater, forming a pond that evaporated eons ago.

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The Moon, Mars, or Beyond? By Jeffrey Winters

Now that one septuagenarian has orbited Earth, Discover editor Sarah Richardson asked former astronauts if they too longed to return to space.

Walter Cunningham WALTER CUNNINGHAM, 66, flew on Apollo 7 in 1968, the first manned Apollo flight, which orbited Earth. He is now the president of Acorn Ventures, a technology consulting firm.

"You bet. I volunteered. I don't care where I would go as long as I'm on a rocket. At my age, you're just glad to be on the ride. It'd be a whole lot easier--I wouldn't have the responsibility. I'd be a passenger, just like John. I think the resources of NASA could be put to better use, but I'm happy for John, just like I'd be happy for me."

Charles Duke CHARLES DUKE, 63, was the lunar-module pilot on Apollo 16, the fifth manned lunar mission, which landed in the lunar highlands and collected 213 pounds of rocks.

"I daydream about it every once in a while. I'd like to go back to the moon. We'd be a lot more perceptive the second time around. I hope [John Glenn's flight] will broaden the opportunities for people to go and experience the exhilaration of spaceflight as well as the incomparable beauty of deep space. I think one of the most significant events [of the space program] was the first view of Earth on the way to the moon--the whole Earth and all of North America visible and almost free of clouds."

Harrison Schmitt HARRISON SCHMITT, 63, was the lunar-module pilot for Apollo 17, the sixth--and last--lunar mission. Schmitt was also a senator from New Mexico between 1977 and 1982.

"I think all the astronauts, including me, would be interested. Some are probably married, like I am. And many of their wives would probably like to go this time. I think the next big movement into space will be going to the moon to harvest its resources, both for use on Earth and for use in space. That's what I would like to participate in. I would like to return, and I think everyone who has been there would like to as well."

Alan Bean ALAN BEAN, 66, was the lunar-module pilot on Apollo 12, the second manned flight to land on the moon. He is now a painter; some of his lunarscapes are collected in his new book, Apollo: An Eyewitness Account by an Astronaut/Explorer Artist/Moonwalker.

"I left the space program to be an artist. I thought that although there were people at NASA who could fly the space shuttle as good or better than I could, nobody who had been to the moon was interested in painting it the way I can. So that's why I left--to paint my experiences. A couple of hundred years from now, people might be glad I did.

"This is going to be one of the more important shuttle missions. Right now most people believe space is for young men and women in the prime of life--scientists and technicians and test pilots--and that's pretty much what it is. But I think this event is going to change that attitude. People will realize that old people, young people, kids--everybody--can travel in space. And when people begin to think like that, things change. John Glenn is really the best person to do this because he's a great communicator.

"Our country is not even 300 years old. Maybe in another 300 years there will be vacation spots on the moon and Mars. And believe me, going into space is interesting. Going to the moon is interesting. Going to Mars will probably be even more interesting, and people will pay to go. It's going to be a bonanza."

William Anders WILLIAM ANDERS, 65, flew on Apollo 8 in 1968. It was the first manned mission to circle the moon. Until his retirement six years ago, Anders was the chairman of General Dynamics, a major defense contracting firm.

"I'd like to go into Earth orbit, because during our Apollo 8 flight we were so busy we didn't have a chance to look out until we were 40,000 miles away. I got in trouble with the commander because I tried to sneak a peek. I'd also like to go to the moon, but NASA doesn't have any plans for that right now. I don't see a 60-year-old guy walking on the moon. By the time I'm 100, maybe they would do it. Somebody ought to go back to the moon. Quit fantasizing about Mars for a while. Mars is much, much harder.

"After my flight, I made speeches about being able to buy an Earth-orbit tour for your wife and yourself within 30 years--by the time I was 60 or 70. Instead of going to Acapulco on the Love Boat, you would go around Earth looking out the window on the tour shuttle. That hasn't happened. Maybe in the next 30 years--maybe by the time I'm 90."

Thomas Stafford THOMAS STAFFORD, 68, flew on two Gemini missions and two Apollo missions. Aboard Apollo 10 in 1969, Stafford performed one of the first dress rehearsals for a lunar landing. In 1975, on Apollo 18, he and two other Americans docked with Soyuz 19, crewed by two cosmonauts. It was the first U.S.-Soviet Union rendezvous in space.

"Well, yes, I'd like to go back in space again, but not this instant. I'd have to give up too many things. But in a few years it might be super. My wife said I'd have to wait until I broke John's record--that's another ten years. I wouldn't mind another quick trip back to the moon. Didn't make it last time--our lunar module was too heavy to land. But I don't think it's in the cards to go back there. I'd love to see us go back to the moon, but all the physical training, all that hopping around, I don't know if I could do it. I'd just be happy with Earth orbit.

"I'm a great advocate of going to Mars. But the problem is that trip would be a little long, 180 to 270 days out there, depending on when you launch. I think I'll watch that one from the sidelines."

James Lovell JAMES LOVELL, 70, flew two missions in Earth orbit--Gemini 7 and Gemini 12--and piloted the command module on Apollo 8. He was also the commander on Apollo 13, the near-fatal 1970 lunar mission in which an oxygen tank burst into flames. Lovell managed to navigate the craft around the moon and back to Earth.

"I think it would be very, very nice to go back. I offered to be Glenn's backup, but I was too young. . . . The shuttle is almost like getting on United Airlines now. I think one thing John's going to prove is that age is not really a factor. As a matter of fact, age has never really been a factor in spaceflight--we've had commanders of shuttles who were 60 or 61 years old. Once your stomach gets used to zero gravity, just about anybody can go into space. It's getting back to a one-g environment that's difficult."

Walter Schirra WALTER SCHIRRA, 75, orbited Earth in Mercury 8 and Gemini 6, the first mission to rendezvous with another capsule. In 1968 he was commander of Apollo 7.

"Actually, I'm not at all interested in going back into space. I went up for a long time and I found it extremely boring just orbiting Earth for 11 days. A lot of people get excited about going into space, and I appreciate that--the launch, the landing, and maybe a beautiful view. But after a few days, it kind of pales.

"If you go to the moon and back, it might be okay. That's the most convenient place. To go anyplace else, like Mars, anybody can have my turn. That's roughly a three-year trip, and no human has been away from land, let alone Earth, for more than a year. Some people have this fantasy about how they can hibernate in space that long. Having been in orbit for 11 days, I can tell you it gets very boring. Now it might be exciting to rendezvous with Mir or a space station. But to sit up there for a long period of time, unless you're doing something constructive, won't make tourists happy."

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Highlights of the Year By Jeffrey Winters

The Second Biggest Bang. Gamma-ray bursts--spasms of high-energy radiation--have puzzled astronomers for years. In May, astronomers reported conclusive evidence that the bursts come from distant corners of the universe, not from near our own galaxy as some had argued. Thus, each burst must be unimaginably powerful. In fact, astronomers claim that the only event to surpass the energy of a gamma-ray burst was the Big Bang itself. What actually causes the bursts is still a mystery, but catastrophes such as the collision of a neutron star and a black hole have been proposed.

Our Wet Moon. The Lunar Prospector, which reached the moon last January, detected evidence of 6 billion tons of ice near the lunar poles--enough to cover New Jersey with a foot of water. The craft also detected signs that the moon has a solid iron core 300 to 500 miles in diameter.

There Goes the Neighborhood. A refined estimate in March puts the sun a mere 23,000 light-years from the center of our galaxy, 5,000 light-years closer than astronomers had thought.

The universe is older and lighter than previously estimated, several teams of astronomers reported last January. Through studies of distant supernovas and galactic clusters, the age of the universe was calculated to be about 15 billion years, old enough to account for the age of the oldest stars. These studies also suggest that there is much less mass in the universe than is needed for gravity to halt its expansion.

Two newly discovered moons of Uranus have been named Caliban and Sycorax, after the characters in Shakespeare's Tempest.

An intense pulse of radiation bombarded Earth's atmosphere in August. The gamma rays and X-rays came from a star 20,000 light-years away--SGR1900+14, a member of a newly discovered class of stars called magnetars, which are thought to be rapidly spinning neutron stars with enormous magnetic fields. The radiation pulse temporarily knocked out two satellites.

Although its primary mission ended in 1997, the Galileo probe continues to send back data about Jupiter and its moons. Among the findings: evidence of an ocean on Callisto; salty deposits on Europa, probably also from a subsurface ocean; and a close look at storms raging at the Great Red Spot.

The most distant galaxies in the universe were detected in October. Light from the oldest of them dates back to when the universe was only about 750 million years old.

Several more planets were discovered around distant stars. One has an orbit similar to Earth's, though the planet itself is probably larger than Jupiter. A new instrument--a spectrometer-interferometer hybrid--was demonstrated in June. It may be sensitive enough to detect a planet as small as Earth around another star.
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