NASA's Mars Odyssey spacecraft watches comet flyby

Artist's concept of NASA's Mars Odyssey spacecraft. 

Credit: NASA/JPL-Caltech

The longest-lived robot ever sent to Mars came through its latest challenge in good health, reporting home on schedule after sheltering behind Mars from possible comet dust.

NASA's Mars Odyssey was out of communications with Earth, as planned, while conducting observations of comet C/2013 A1 Siding Spring on Sunday, Oct. 19, as the comet flew near Mars.

The comet sped within about 88,000 miles (139,500 kilometers) of Mars, equivalent to about one-third of the distance between Earth and Earth's moon.

Mars Odyssey had performed a maneuver on Aug. 5 to adjust the timing of its orbit so that it would be shielded by Mars itself during the minutes, around 1 p.m. PDT (4 p.m. EDT) today, when computer modeling projected a slight risk from high-velocity dust particles in the comet's tail.

"The telemetry received from Mars Odyssey this afternoon confirms not only that the spacecraft is in fine health but also that it conducted the planned observations of comet C/2013 A1 Siding Spring within hours of the comet's closest approach to Mars," said Odyssey Mission Manager Chris Potts of NASA's Jet Propulsion Laboratory, Pasadena, Calif., speaking from mission operations center at Lockheed Martin Space Systems, Denver.

THEMIS

Comet C/2013 A1 Siding Spring observations were made by the orbiter's Thermal Emission Imaging System (THEMIS).

Resulting images are expected in coming days after the data is downlinked to Earth and processed.

THEMIS is also scheduled to record a combined image of the comet and a portion of Mars later this week.

In addition, the Odyssey mission is using the spacecraft's Neutron Spectrometer (NS) and the Russian-made, High Energy Neutron detector (HEND) to assess possible effects on Mars' atmosphere of dust and gas from the comet.

Three NASA Mars orbiters, two Mars rovers and other assets on Earth and in space are studying comet Siding Spring.

This comet is making its first visit this close to the sun from the outer solar system's Oort Cloud, so the concerted campaign of observations may yield fresh clues to our solar system's earliest days more than 4 billion years ago.

Following the comet flyby, operations teams have also confirmed the good health of NASA's Mars Reconnaissance Orbiter and of NASA's Mars Atmosphere and Volatile EvolutioN (MAVEN) orbiter.

Mars Odyssey has worked at the Red Planet longer than any other Mars mission in history.

NASA launched the spacecraft on April 7, 2001, and Mars Odyssey arrived at Mars Oct. 24, 2001.

Besides conducting its own scientific observations, the mission provides a communication relay for robots on the Martian surface.

NASA's Mars Reconnaissance Orbiter safely watches Comet Siding Spring FlyBy

NASA's Mars Reconnaissance Orbiter, which has sent home more data about Mars than all other missions combined, is also now providing data about a comet that buzzed The Red Planet today (Oct. 19).

The orbiter continues operating in good health after sheltering behind Mars during the half hour when high-velocity dust particles from comet C/2013 A1 Siding Spring had the most chance of reaching the paths of Mars orbiters.

The Comet Siding Spring C/2013 A1 is indicated on this image as it passes Mars, seen here shining brightly on the bottom left.

Credit: Slooh

maintained radio communications with Earth throughout the comet's closest approach, at 11:27 a.m. PDT (2:27 p.m. EDT), and the peak dust-risk period centered about 100 minutes later.

"The spacecraft performed flawlessly throughout the comet flyby," said Mars Reconnaissance Orbiter Project Manager Dan Johnston of NASA's Jet Propulsion Laboratory, Pasadena, California. "It maneuvered for the planned observations of the comet and emerged unscathed."

Following the critical period of dust flux, the orbiter is communicating at 1.5 megabits per second with NASA's Deep Space Network.

It remained on Side A of its two redundant computers, and all subsystems are working as expected.

The remainder of the NASA Mars orbiters, Mars Express and ISRO's MOM, appear to be in good health and unaffected by the comet flyby.

An artist impression of the passing of Comet Siding Spring as seen by Curiosity Rover on Mars.

Credit: SLOOH

Ultrafast heating of water: This pot boils faster than you can watch

A single terahertz flash can heat the water cloud to 600 degrees centigrade, while leaving all water molecules intact. 

Credit: Oriol Vendrell/DESY

Scientists from the Hamburg Center for Free-Electron Laser Science (CFEL) have devised a novel way to boil water in less than a trillionth of a second.

The theoretical concept, which has not yet been demonstrated in practice, could heat a small amount of water by as much as 600 degrees Celsius in just half a picosecond (a trillionth of a second).

That is much less than the proverbial blink of an eye: one picosecond is to a second what one second is to almost 32 millennia. This would make the technique the fastest water-heating method on Earth.

The novel concept opens up interesting new ways for experiments with heated samples of chemical or biological relevance, as the inventors report in this week's issue of the scientific journal Angewandte Chemie International Edition (Nr. 51, 16 December).

"Water is the single most important medium in which chemical and biological processes take place," explains Deutsches Elektronen-Synchrotron (DESY) scientist Dr. Oriol Vendrell from the Center for Free-Electron Laser Science CFEL, a cooperation of Deutsches Elektronen-Synchrotron (DESY), the University of Hamburg and the German Max Planck Society.

"Water is not just a passive solvent, but plays an important role in the dynamics of biological and chemical processes by stabilising certain chemical compounds and enabling specific reactions."

All it takes for superfast water heating is a concentrated flash of terahertz radiation. Terahertz radiation consists of electromagnetic waves with a frequency between radio waves and infrared.

Terahertz flashes can be generated with devices called free-electron lasers that send accelerated electrons on a well defined slalom course.

The particles emit electromagnetic waves in each bend that add up to an intense laser like pulse. The terahertz pulse changes the strength of the interaction between water molecules in a very short time, which immediately start to vibrate violently.

The scientists calculated the interaction of the terahertz flash with bulk water. The simulations were performed at the Supercomputer Center Jülich and used a total of 200,000 hours of processor time by massively parallel computing.

On a single processor machine this would correspond to about 20 years of computation. "We have calculated that it should be possible to heat up the liquid to about 600 degrees Celsius within just half a picosecond, obtaining a transiently hot and structureless environment still at the density of the liquid, leaving all water molecules intact," explains Vendrell.

The novel method can only heat about one nanolitre (billionth of a litre) in one go. This may sound small, but is large enough for most experiments.

For comparison, ink-jet printers fire droplets that are as small as one picolitre, which is a thousand times less than a nanolitre.

More information: "Ultrafast Energy Transfer to Liquid Water by Sub-Picosecond High- Intensity Terahertz Pulses: An Ab Initio Molecular Dynamics Study"; Pankaj Kr. Mishra, Oriol Vendrell and Robin Santra; Angewandte Chemie International Edition, Vol. 52, Nr. 51, p. 13685-13687, 16. Dezember 2013; DOI: 10.1002/anie.201305991

DLR Portal - Early bird special – watch the TanDEM-X launch live

DLR Portal - Early bird special – watch the TanDEM-X launch live



TanDEM-X, Germany's new Earth observation satellite, is scheduled for launch on Monday, 21 June 2010 at 04:14 CEST. Together with its twin, TerraSAR-X, TanDEM-X will survey all 150 million square kilometres of Earth's land surface several times during its three-year mission. We will stream the TanDEM-X launch live from the Baikonur Cosmodrome in Kazakhstan, as well as an exclusive infotainment programme from the control centre in Oberpfaffenhofen, Germany.