Washington: NASA scientists have captured a peanut-shaped asteroid that approached close to Earth last weekend. The next time an asteroid will approach Earth this close will be in 2054.
The asteroid named 1999 JD6 appears to be a contact binary — an asteroid with two lobes that are stuck together.
On July 24, the asteroid made its closest approach to Earth at a distance of about 7.2 million kms, or about 19 times the distance from Earth to the moon.
“Radar imaging has shown that about 15 percent of near-Earth asteroids larger than 600 feet, including 1999 JD6, have this sort of lobed, peanut shape,” said Lance Benner of NASA’s Jet Propulsion Laboratory in Pasadena, California, in a statement.
To obtain the views, researchers paired NASA’s Deep Space Network antenna at Goldstone, California with the National Science Foundation Green Bank Telescope in West Virginia.
The images show the asteroid is highly elongated, with a length of approximately two kms on its long axis.
NASA’s asteroid-tracking mission places a high priority on tracking asteroids and protecting our home planet from them.
Sue Finley, now 80 years old and NASA’s longest-serving female employee, recalls her early days with the space agency when she worked as a human “computer,” calculating rocket trajectories by hand at a time when computers were huge and expensive to operate.
Finley arrived at Jet Propulsion Laboratory (JPL) in Pasadena, California, in January 1958, one week before the U.S. Army launched Explorer 1, America’s first earth satellite.
“It was a very big deal,” she recalls of the launch, a response to the launches a few months earlier of the first satellites, Sputnik 1 and 2, from the former Soviet Union.
She was at JPL for Pioneer 1, the first satellite sent aloft by the newly formed National Aeronautics and Space Administration (NASA) in late 1958, which marked the beginning of the international space race.
Unmanned space probes
Since then, Finley has had a role in nearly every U.S. unmanned space probe, and some missions of other nations.
There were failures to overcome and spectacular successes, but always new goals as scientists expanded our knowledge of the earth and solar system.
“We were certainly proud,” she says of NASA accomplishments, “but you just go to the next thing.”
Finley has been through several career changes with the space agency, one of the most important when NASA phased out human computers, moving, initially, to simple electronic versions.
“We got little tiny computers,” she recalls. “One I had 16 wires, jumper cables to code with. One had 10 pegboards that you programmed with.”
As modern computers took over navigational tasks, Finley developed and tested software as a subsystem engineer.
Among her career highlights: the Vega mission, a Soviet-French collaboration with Venus, and Halley’s Comet, which received navigational help from NASA and dropped balloons into the atmosphere of Venus.
She had to change the software for the antenna that tracked the mission, “and it worked,” Finley recalls. “Everything worked. That’s what was so exciting!”
Finley has worked since 1980 on NASA’s Deep Space Network, which coordinates satellite facilities in California, Spain and Australia that allow communication with space probes.
Highlights of NASA career
Career highlights include developing software that generates audio tones sent back from spacecraft, informing engineers on the ground what is happening in space. It was first developed for the Mars missions.
Each tone has a meaning that communicates data, noted one of Finley’s colleagues, Stephen Lichten.
“If a parachute opened, it would send a tone,” Lichten, manager for special projects for the Deep Space Network, said.
“The spacecraft lets go of its heat shield, and it would send a different tone, and so engineers like Sue were here listening for those special frequencies which told them the spacecraft was telling them what it has just done,” he said.
He notes that Finley also helped develop communication arrays that combine multiple antennas to act in unison and other advances that now crucial to space missions.
Lichten once shared an office with Finley and says she inspired her younger colleagues.
“There was a parade of people coming in constantly, to ask her advice, to ask her questions,” he recalls. “This was during the Venus balloon mission days and I realized that Sue was regarded as sort of a guru at JPL.”
Finley has been involved with nearly every advance in space communications in recent decades, and she continues her work today, Lichten said.
There are many more women at NASA today than there were when she started, and Finley said she tells young women to be inquisitive.
“I tell them to never be afraid to ask questions, never be afraid to say you don’t know,” she said.
After nearly six decades at the space agency, a mother of two grown sons and a mentor to her colleagues, Finley has no plans of retiring.
“There’s nothing else I want to do,” she said. “And so far, they need me.”
As they have since the earliest days of the space agency. (VOA)
Florida, November 19, 2017: NASA captured 20 years of changing seasons on Earth in a striking new global map of the home planet.
The data visualization, released this week, shows Earth’s fluctuations as seen from space.
The polar ice caps and snow cover are shown ebbing and flowing with the seasons. The varying ocean shades of blue, green, red and purple depict the abundance — or lack — of undersea life.
“It’s like watching the Earth breathe. It’s really remarkable,” said NASA oceanographer Jeremy Werdell, who took part in the project.
Two decades — from September 1997 to this past September — are crunched into 2½ minutes of viewing.
Werdell finds the imagery mesmerizing. “It’s like all of my senses are being transported into space, and then you can compress time and rewind it, and just continually watch this kind of visualization,” he said Friday.
Werdell said the visualization shows spring coming earlier and autumn lasting longer in the Northern Hemisphere. Also noticeable to him is the receding of the Arctic ice caps over time — and, though less obvious, the Antarctic, too.
On the sea side, Werdell was struck by “this hugely productive bloom of biology” that exploded in the Pacific along the equator from 1997 to 1998 — when a water-warming El Nino merged into cooling La Nina. This algae bloom is evident by a line of bright green.
In considerably smaller Lake Erie, more and more contaminating algae blooms are apparent — appearing red and yellow.
All this data can provide resources for policymakers as well as commercial fishermen and many others, according to Werdell.
Programmer Alex Kekesi of NASA’s Goddard Space Flight Center in Maryland said it took three months to complete the visualization, using satellite imagery.
Just like our Earth, the visualization will continually change, officials said, as computer systems improve, new remote-sensing satellites are launched and more observations are made. (VOA)
London: A 10-km wide asteroid that wiped out dinosaurs when it crashed into earth over 65 million years ago contains a rare metal — iridium — that could be used in the effective treatment of cancer, researchers have found.
Scientists from the UK and China have demonstrated that iridium — a rare metal delivered to Earth by the asteroid — can be used to kill cancer without harming healthy cells.
Laser-based techniques are emerging as viable treatments for cancer, targeting tumours far more precisely than the shotgun blast of radiation and chemotherapy. Researchers from the University of Warwick in the UK and Sun Yat-Sen University in China have found that laser light can turn iridium into an effective cancer killer, the newatlas.com reported.
The team created a compound of iridium and organic materials, and then introduced it into a lung cancer tumour grown in the lab. When red laser light is shone onto it through the skin, the compound is activated, converting the oxygen in the tumour into singlet oxygen, a poisonous form of the element that effectively kills the cancer cells from the inside. With cancer becoming resistant to certain treatments, it’s crucial to find new methods such as this.
Further study found that the compound was effective as it managed to penetrate every layer of the tumour.
The team used ultra-high resolution mass spectrometry to highlight which proteins in the cancer cells were being targeted. They found that the compound had damaged proteins that manage heat shock stress and glucose metabolism, which are known to be crucial molecules for cancer’s survival.
When the researchers tested the iridium compound on a clump of non-cancerous tissue they found it had no effect, meaning it seems to be a highly targeted treatment that doesn’t attack healthy cells. The research was published in the journal Angewandte Chemie.
Iridium is relatively rare on Earth naturally, but scientists have found a spike in the Chicxulub crater, an impact crater buried underneath the YucatÃ¡n Peninsula in Mexico, which is often associated with the asteroid impact that wiped out the dinosaurs.
“The precious metal platinum is already used in more than 50 per cent of cancer chemotherapies,” says Peter Sadler, lead author of the study. “The potential of other precious metals such as iridium to provide new targeted drugs that attack cancer cells in completely new ways and combat resistance, and which can be used safely with the minimum of side-effects, is now being explored. It’s certainly now time to try to make good medical use of the iridium delivered to us by an asteroid 66 million years ago!” — IANS