The MESSENGER trajectory correction maneuver 11 (TCM 11) on September 12 lasted just under four minutes and adjusted the spacecraft's velocity by about 1.68 meters per second (5.5 feet per second). The short-duration maneuver kept MESSENGER on track for next month's Venus flyby.

Tuesday's maneuver started at 7 p.m. EDT; mission controllers at The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., verified the start of the maneuver about 12 minutes later, when the first signals indicating thruster activity reached NASA's Deep Space Network tracking station outside Canberra, Australia.

Cassini's Visual and Infrared Mapping Spectrometer (VIMS) has detected what appears to be a massive ethane cloud surrounding Titan's north pole. The cloud might be snowing ethane snowflakes into methane lakes below.

The cloud may be the clue needed in solving a puzzle that has confounded scientists who so far have seen little evidence of a veil of ethane clouds and surface liquids originally thought extensive enough to cover the entire surface of Titan with a 300-meter-deep ocean.

This image from Cassini's radar instrument shows an impact crater with a diameter of 30 kilometers (19 miles) on the surface of Saturn's moon Titan.

Cassini data have only revealed three definite impact craters on Titan so far, so each new discovery adds significantly to our body of knowledge. Impact craters are particularly important, as their shapes give scientists insight into the structure of the crust beneath Titan's surface.

This image depicts Saturn's moon Titan as seen by the visual and infrared mapping spectrometer after closest approach on a July 22, 2006, flyby.

The image was generated using the 5 micron wavelength for red, the 2 micron wavelength for green and the 1.2 micron wavelength for blue. The clouds, circled in the annotated version, are of the type seen previously and reported in the journal Science. The image shows the clouds spreading out along the 40-degree-south latitude line.

This composite image, composed of two images taken with Cassini's visual and infrared mapping spectrometer, shows a crescent view of Saturn's moon Titan.

The data were obtained during a flyby on July 22, 2006, at a distance of 15,700 kilometers (9,700 miles) from Titan. The image was constructed from images taken at wavelengths of 1.26 microns shown in blue, 2 microns shown in green, and 5 microns shown in red.

NASA's newest spacecraft at Mars has completed the challenging half-year task of shaping its orbit to the nearly circular, low-altitude pattern from which it will scrutinize the planet.

The Mars Reconnaissance Orbiter fired its six intermediate-size thrusters for 12.5 minutes Monday afternoon, Sept. 11, shifting the low point of its orbit to stay near the Martian south pole and the high point to stay near the north pole. The altitude of the orbit ranges from 250 kilometers (155 miles) to 316 kilometers (196 miles) above the surface.

Mars Global Surveyor (MGS) has now been orbiting Mars for 9 years! It was the evening of 11 September 1997, Pacific Daylight time, but it was early in the morning on 12 September 1997, Greenwich Mean Time, when MGS fired its engines to slow down and drop into an elliptical orbit around Mars.

The Mars Orbiter Camera (MOC) began acquiring its first images just a few days later. Today, the MGS MOC remains extremely healthy and ready to begin its 10th year of operations.

After more than 10 years and 40,000 orbits, a resilient NASA satellite continues to unveil the mysteries of the Earth's aurora borealis and australis, also known as the northern and southern lights.

The Fast Auroral SnapshoT (FAST) satellite was launched from Vandenberg Air Force Base in California, on August 21, 1996, into a near polar orbit. "In many aspects, the FAST mission has revolutionized our view of the aurora," said Dr. Charles W. Carlson, FAST Principal Investigator, University of California, Berkeley.

Solar flares are tremendous explosions on the surface of our Sun, releasing as much energy as a billion megatons of TNT in the form of radiation, high energy particles and magnetic fields.

The Sun's magnetic fields are known to be an extremely important factor in producing the energy for flaring and when these magnetic fields lines clash together, dragging hot gas with them, an enormous maelstrom of energy is released.

Astronomers using ESA's orbiting gamma-ray observatory, Integral, have taken an important step towards estimating how many black holes there are in the Universe.

An international team, lead by Eugene Churazov and Rashid Sunyaev, Space Research Institute, Moscow, and involving scientists from all groups of the Integral consortium, used the Earth as a giant shield to watch the number of tell-tale gamma rays from the distant Universe dwindle to zero, as our planet blocked their view.

Astronomers using Hubble Space Telescope have photographed one of the smallest objects ever seen around a normal star beyond our Sun. Weighing in at 12 times the mass of Jupiter, the object is small enough to be a planet. The conundrum is that it's also large enough to be a brown dwarf, a failed star.

The Hubble observation of the diminutive companion to the low-mass red dwarf star CHXR 73 is a dramatic reminder that astronomers do not have a consensus in deciding which objects orbiting other stars are truly planets -- even though they have at last agreed on how they will apply the definition of "planet" to objects inside our solar system.

NASA's Mars rover Opportunity is closing in on what may be the grandest overlook and richest science trove of its long mission.

During the next two weeks, the robotic geologist is likely to reach the rim of a hole in the Martian surface wider and deeper than any it has visited. The crater, known as "Victoria," is approximately 750 meters (half a mile) wide and 70 meters (230 feet) deep.

In his latest column, New Horizons Principal Investigator Alan Stern weighs in on the International Astronomical Union's recent decision to change Pluto's planetary status. His conclusion: the IAU definition of a planet is not only unworkable and unteachable, but so scientifically flawed and internally contradictory that it cannot be strongly defended against claims of scientific sloppiness, "ir-rigor," and cogent classification. Read more.

Analysis of images obtained at the Canada-France-Hawaii Telescope by Christian Veillet have revealed a plume of debris thrown up when SMART-1 imapcted the lunar surface.

The observation were made with the WIRCam wide-field infrared camera with 10s exposure time througha an H2 narrow-band filter at 2122 nanometers with a 32 nanometers bandwidth. Each image is approximately 2'x 2', equating to 200 km x 200 km.

The highest-resolution camera on NASA's Pluto-bound New Horizons spacecraft is seeing stars, and mission scientists and engineers couldn't be more excited.

Last week the Long Range Reconnaissance Imager (LORRI) opened its protective cover and took its first image in space, of Messier 7, a star cluster in our Milky Way galaxy. The electronic snapshot also meant that all seven New Horizons science instruments have now operated in space and returned good data since the spacecraft launched in January 2006.