Tuesday, November 8, 2011
Thursday, October 27, 2011
The Fabric of the Cosmos, a four-hour series based on the book by renowned physicist and author Brian Greene, takes us to the frontiers of physics to see how scientists are piecing together the most complete picture yet of space, time, and the universe. With each step, audiences will discover that just beneath the surface of our everyday experience lies a world we’d hardly recognize — a startling world far stranger and more wondrous than anyone expected.
Brian Greene is going to let you in on a secret: We've all been deceived. Our perceptions of time and space have led us astray. Much of what we thought we knew about our universe — that the past has already happened and the future is yet to be, that space is just an empty void, that our universe is the only universe that exists — just might be wrong.
Interweaving provocative theories, experiments, and stories with crystal-clear explanations and imaginative metaphors like those that defined the groundbreaking and highly acclaimed series The Elegant Universe, The Fabric Of The Cosmos aims to be the most compelling, visual, and comprehensive picture of modern physics ever seen on television.
Airing Wednesdays: 11/2, 11/9, 11/16 and 11/23, at 9pm on WGBH 2
Tuesday, April 12, 2011
Friday, November 9, 2012
By Mark Stencel | Monday, August 6, 2012
The best place to stand in the entire solar system at 1:14 a.m. ET Monday was about 150 million miles away, at the bottom of Gale Crater near the equator of the Red Planet.
Looking west around mid-afternoon local time, a Martian bystander would have seen a rocket-powered alien spacecraft approach and then hover about 60 feet over the rock-strewn plain between the crater walls and the towering slopes of nearby Mount Sharp.
A gangly vehicle, about the size of a small car on Earth, descended from the spacecraft on nylon cords amid blowing crimson dust. As soon as this machine touched the soil with its six wheels, its delivery craft abruptly disconnected the cables and, with the last of its fuel, safely careened away from its passenger. NASA's new Mars rover, Curiosity, had landed.
Fourteen minutes later, news of these strange happenings reached the people on Earth who were responsible:
With those words, the mission control team at the space agency's Jet Propulsion Laboratory in Pasadena, Calif., erupted in cheers, applause and hugs. And as the first pictures began to arrive from their nuclear-powered explorer, the celebrations grew louder and continued well into a televised news conference an hour later.
"Needless to say there's a lot of excitement in this room," said the laboratory's director, Charles Elachi.
When it comes to visitors like the $2.5-billion Curiosity rover, Mars has been a reclusive, get-off-of-my-lawn host. Of 13 previous attempts to land space probes on the Red Planet over the past four decades, nearly half failed or immediately lost contact.
Those odds were enough to make for a tense scene at mission control in the days and hours leading up the landing. "You can't believe the tension and uncertainty here at JPL," NPR science correspondent Joe Palca reported from the laboratory. "The anxiety just couldn't be denied."
The novel use of the rocket-powered "sky crane" to lower the one-ton robot to the Martian surface only added to the drama.
"I was on the edge of my seat," former astronaut and NASA Administrator Charlie Bolden Jr. told NASA TV moments after the landing.
With the suspenseful landing behind them, mission controllers quickly turned their attention to Curiosity's coming months of work on the Martian surface. The rover is expected to spend two years exploring Gale Crater and the three-mile-high mountain within it.
"Tomorrow," JPL's Elachi said, "we're going to start exploring Mars."
NASA TV has been streaming video of the overnight events at the Jet Propulsion Laboratory and plans to carry the next scheduled news conference at Noon ET.
Our earlier updates appear below.
Update at 4:05 a.m. ET. More Images
After a helpful space probe in Mars orbit again passed within range of Curiosity's transmissions, a new batch of photos arrived in Pasadena. In one of the black-and-white images, the shadowy rim of Gale Crater was clearly visible on the horizon.
Update at 1:15 a.m. ET. 'A Lot Has To Go Right'
Mission control just got word that Curiosity successfully separated from the cruise stage that has carried the rover since its launch from the Cape Canaveral Air Force Station in Florida — 36 weeks and millions of miles ago.
Now things begin to move fast. As science correspondent Joe Palca told our Newscast unit, "A lot has to go right for the rover... to land safely":
"A heat shield has to slow the spacecraft from 13,000 mph to about 800 mph. Then a giant supersonic parachute has to unfurl properly to slow the rover further to about 200 mph. Then onboard radar has to detect the surface, and rocket engines aboard a kind of jet pack have to fire, slowing Curiosity to a crawl. Finally, a bridle has to lower the rover from the jet pack to the surface."
Easy enough, right? A NASA video calls the whole chain of events "seven minutes of terror." You'll find that video and a gallery of artist renderings depicting key moments in Curiosity's descent and landing in Joe's profile of one of the engineers behind this intricate plan.
On Sunday's All Things Considered, Joe also talked with Richard Kornfeld, a senior engineer on the landing team, about the 14-minute delay before transmissions reach Earth. For people like Kornfeld, this has to make the Olympics coverage feel real-time.
Update at 1 a.m. ET. The 'Bermuda Triangle' Of Space?
Not that we want to jinx Curiosity, but it's worth a moment before the descent begins to go back through Mars' well-earned reputation as dangerous destination for space probes.
We mentioned that 7 of the 13 previous attempts to reach the Martian surface were successful. The first, the Soviet Union's Mars 3 lander in 1971, arrived during a sandstorm and only sent back one partial, fuzzy image before communication was lost seconds later.
Of the six failures, the landing vehicles crashed, lost contact on the way down or on the ground, missed Mars entirely, or never made it out of Earth orbit. The most recent losses were the European Space Agency's Beagle 2 in 2003 and the U.S. Polar Lander in 1999. The others were led by the Soviet Union or Russia.
That said, the overall U.S. track record with Mars landings has been a solid six-for-seven, including:
Update at 12:20 a.m. ET. The Landing Site
Curiosity's destination is Gale Crater, where the six-wheeled rover is expected to spend at least two years looking for signs of water or possibly a long-gone lake.
Samuel Kounaves, a chemistry professor at Tufts University, talked to NPR's Joe Palca and science writer Jessica Stoller-Conrad about the mission's scientific goals. The rover "is not going to be looking for life directly, but it's going to be looking for past habitability," Kounaves told them. "We're looking to see if the elements required for life are there."
Gale Crater is nearly 100 miles across. Curiosity will try to land in a relatively flat area between the crater's rim and the steep slopes of Mount Sharp. The landing zone — 4 miles wide and 12 miles long — was narrowed recently to try to place Curiosity closer to the three-mile-high mountain, where scientists hope the rover will uncover layers of Martian history.
Tuesday, July 31, 2012
Mission control for the telescope is a small room on the University of California, Berkeley, campus, where about a dozen people with headsets rarely look up from their screens.
Fiona Harrison, a professor of physics and astronomy at the California Institute of Technology, is the principal scientist for the mission. If there's one word that describes her past few weeks, it's "nail-biting," she says.
The beginning of a space telescope's life is particularly stressful. It has to be switched on remotely, including the unfurling of a 33-foot arm that will act like a giant telephoto lens.
Now, the $170 million telescope is just about ready to begin its hunt for black holes.
"We're not actually seeing the black hole," Harrison says. "What you're actually seeing is the stuff that's attracted to it."
Harrison says they're called black holes because not even light can escape their gravity. But black holes aren't passive — they pull in tons of dust and gas. The material swirls around faster and faster, just like a bathtub drain, and gets hotter.
"The material is so hot that it radiates high-energy X-rays," she says, just like the ones doctors use. She says researchers observed them before, but it's like reading a book without your glasses.
"We know there's a story there, we know there's text, but we haven't been able to read the letters," she says.
With NuSTAR, they'll be able to see these X-rays at a higher resolution than ever before.
"It's incredibly exciting because we don't actually know what the text is going to say. And now we're going to be able to read it clearly for the first time," she says.
Harrison hopes the telescope will unlock some of the mysteries around black holes — like how they grow.
Eliot Quataert, an astronomy professor at UC Berkeley who is not on the mission staff, says black holes grow just like we do — by eating.
"They eat dramatically, but rarely," he says.
And at the very center of our galaxy, there's a super massive black hole that has eaten quite a bit. But we're still here.
"The misconception that's out there is that black holes are a vacuum cleaner that will inevitably suck in everything around them," Quataert says. For the most part, black holes are on a forced diet — they've already eaten everything close by.
"But then every once in a while, there will be a lot of gas that gets funneled to the center of a galaxy, and the black hole will grow in a big spurt," he says.
Quataert says seeing this black hole mealtime with the telescope could reveal more about the extreme physics behind it. That could answer questions about how galaxies form. UC Berkeley astronomer Joshua Bloom hopes NuSTAR will find another strange phenomenon: black hole burps.
"You can think about this black hole burping as if you're on a feeding frenzy and you can't fit that many hot dogs in your mouth," Bloom says.
Early last year, Bloom and other astronomers noticed a black hole devouring a star. The black hole spit out a huge jet of material — a burp. That might sound weird, since nothing can escape a black hole, right?
"These are sort of the Las Vegas of the universe. What happens in a black hole stays inside of a black hole. But on the outskirts of them, that is where there's tremendous action," he says.
Bloom says they're hoping to see more of these rare events and others that are still unknown to astronomers. The NuSTAR space telescope's mission is expected to last at least two years.