Showing posts with label sets. Show all posts
Showing posts with label sets. Show all posts

Tuesday, July 29, 2014

NASA Curiosity Rover: Long-lived rover sets off-world driving record

This natural colour view from NASA's Mars Exploration Rover Opportunity shows "Lunokhod Crater," which lies south of Solander Point on the west rim of Endeavour Crater. 

Credit: NASA/JPL-Caltech /Cornell /Arizona State Univ.

NASA's Opportunity Mars rover, which landed on the Red Planet in 2004, now holds the off-Earth roving distance record after accruing 25 miles (40 kilometers) of driving.

The previous record was held by the Soviet Union's Lunokhod 2 rover.

"Opportunity has driven farther than any other wheeled vehicle on another world," said Mars Exploration Rover Project Manager John Callas, of NASA's Jet Propulsion Laboratory in Pasadena, California.

"This is so remarkable considering Opportunity was intended to drive about one kilometer and was never designed for distance but what is really important is not how many miles the rover has racked up, but how much exploration and discovery we have accomplished over that distance."

A drive of 157 feet (48 meters) on July 27 put Opportunity's total odometry at 25.01 miles (40.25 kilometers).

This month's driving brought the rover southward along the western rim of Endeavour Crater.

The rover had driven more than 20 miles (32 kilometers) before arriving at Endeavour Crater in 2011, where it has examined outcrops on the crater's rim containing clay and sulfate-bearing minerals.

The sites are yielding evidence of ancient environments with less acidic water than those examined at Opportunity's landing site.

If the rover can continue to operate the distance of a marathon, 26.2 miles (about 42.2 kilometers), it will approach the next major investigation site mission scientists have dubbed "Marathon Valley."

Observations from spacecraft orbiting Mars suggest several clay minerals are exposed close together at this valley site, surrounded by steep slopes where the relationships among different layers may be evident.

The Russian Lunokhod 2 rover, a successor to the first Lunokhod mission in 1970, landed on Earth's moon on Jan. 15, 1973, where it drove about 24.2 miles (39 kilometers) in less than five months, according to calculations recently made using images from NASA's Lunar Reconnaissance Orbiter (LRO) cameras that reveal Lunokhod 2's tracks.

Irina Karachevtseva at Moscow State University of Geodesy and Cartography's Extraterrestrial Laboratory in Russia, Brad Jolliff of Washington University in St. Louis, Tim Parker of JPL, and others collaborated to verify the map-based methods for computing distances are comparable for Lunokhod-2 and Opportunity.

This chart illustrates comparisons among the distances driven by various wheeled vehicles on the surface of Earth's moon and Mars. 

Of the vehicles shown, the NASA Mars rovers Opportunity and Curiosity are still active and the totals for those two are distances driven as of May 15, 2013.

Credit: NASA/JPL-Caltech

"The Lunokhod missions still stand as two signature accomplishments of what I think of as the first golden age of planetary exploration, the 1960s and '70s," said Steve Squyres of Cornell University in Ithaca, New York, and principal investigator for NASA's twin Mars rovers, Opportunity and Spirit.

"We're in a second golden age now, and what we've tried to do on Mars with Spirit and Opportunity has been very much inspired by the accomplishments of the Lunokhod team on the moon so many years ago. It has been a real honour to follow in their historical wheel tracks."

As Opportunity neared the mileage record earlier this year, the rover team chose the name Lunokhod 2 for a crater about 20 feet (6 meters) in diameter on the outer slope of Endeavour's rim on Mars.

Tuesday, August 7, 2012

How Big Is Infinity? - YouTube



Using the fundamentals of set theory, explore the mind-bending concept of the "infinity of infinities" -- and how it led mathematicians to conclude that math itself contains unanswerable questions.

Lesson by Dennis Wildfogel, animation by Augenblick Studios.

View full lesson: http://ed.ted.com/lessons/how-big-is-infinity

Tuesday, December 1, 2009

LHC sets new world record for energy particle accelarator

CERN's Large Hadron Collider has today become the world's highest energy particle accelerator, having accelerated its twin beams of protons to an energy of 1.18 TeV in the early hours of the morning.

This exceeds the previous world record of 0.98 TeV, which had been held by the US Fermi National Accelerator Laboratory's Tevatron collider since 2001. It marks another important milestone on the road to first physics at the LHC in 2010.

"We are still coming to terms with just how smoothly the LHC commissioning is going," said CERN Director General Rolf Heuer. "It is fantastic. However, we are continuing to take it step by step, and there is still a lot to do before we start physics in 2010. I'm keeping my champagne on ice until then."

These developments come just 10 days after the LHC restart, demonstrating the excellent performance of the machine. First beams were injected into the LHC on Friday 20 November.

Over the following days, the machine's operators circulated beams around the ring alternately in one direction and then the other at the injection energy of 450 GeV, gradually increasing the beam lifetime to around 10 hours. On Monday 23 November, two beams circulated together for the first time, and the four big LHC detectors recorded their first collision data.

Last night's achievement brings further confirmation that the LHC is progressing smoothly towards the objective of first physics early in 2010. The world record energy was first broken yesterday evening, when beam 1 was accelerated from 450 GeV, reaching 1050 GeV (1.05 TeV) at 21:28, Sunday 29 November. Three hours later both LHC beams were successfully accelerated to 1.18 TeV, at 00:44, 30 November.

"I was here 20 years ago when we switched on CERN's last major particle accelerator, LEP," said Research and Technology Director Steve Myers. "I thought that was a great machine to operate, but this is something else. What took us days or weeks with LEP, we're doing in hours with the LHC. So far, it all augurs well for a great research program."

Next on the schedule is a concentrated commissioning phase aimed at increasing the beam intensity before delivering good quantities of collision data to the experiments before Christmas. So far, all the LHC commissioning work has been carried out with a low intensity pilot beam. Higher intensity is needed to provide meaningful proton-proton collision rates.

The current commissioning phase aims to make sure that these higher intensities can be safely handled and that stable conditions can be guaranteed for the experiments during collisions. This phase is estimated to take around a week, after which the LHC will be colliding beams for calibration purposes until the end of the year.

Prof John Womersley, Director Science Programmes at STFC said; "this is another fantastic milestone for the LHC. To see such a complex project make progress at this impressive rate is testament to the tremendous efforts that have been made by all of those involved. I look forward to seeing the continued success of the LHC and to early 2010 when we can expect it to deliver the first data for physics analysis".

First physics at the LHC is scheduled for the first quarter of 2010, at a collision energy of 7 TeV (3.5 TeV per beam).