It's the Martian version of spring break: Curiosity and Opportunity, along with their spacecraft friends circling overhead, will take it easy this month because of the sun's interference. For much of April, the sun blocks the line of sight between Earth and Mars. This celestial alignment — called a Mars solar conjunction — makes it difficult for engineers to send instructions or hear from the flotilla in orbit and on the surface. Such communication blackouts occur every two years when the red planet disappears behind the sun. No new commands are sent since flares and charged particles spewing from the sun can scramble transmission signals and put spacecraft in danger.

When Jupiter’s tides ripped Comet Shoemaker–Levy 9 to shreds, only for the icy chunks to succumb to the intense Jovian gravity, ultimately slamming into the gas giant’s atmosphere, mankind was treated to a rare cosmic spectacle (in human timescales at least). That was the first time in modern history that we saw a comet do battle with a planet… and lose. But next year, astronomers think there’s a chance — albeit a small one — of a neighboring planet getting punched by an icy interplanetary interloper. However, this planet doesn’t have a generously thick atmosphere to soften the blow. Rather than causing bruises in a dense, molecular hydrogen atmosphere, this comet will pass through the atmosphere like it wasn’t even there and hit the planetary surface like a cosmic pile-driver, ripping into the crust. What’s more, we’d have robotic eyes on the ground and in orbit should the worst happen.

ESA’s Mars Express acquired signals from NASA’s Mars Science Laboratory as it delivered the car-sized Curiosity rover onto the Red planet’s surface. ESA’s New Norcia tracking station also picked up signals directly from the NASA mission, 248 million km away at Mars. A key step was completed today in ESA's ongoing support to NASA's Mars Science Laboratory (MSL) mission. Signals recorded by Mars Express during MSL’s entry and descent were successfully received at ESOC, ESA's European Space Operations Centre, Darmstadt, Germany. The open-loop recording of radio Doppler and signal spectrum transmitted by the NASA mission were stored on Mars Express and then downloaded to Earth.

NASA's Mars rover Curiosity may seem like the strong, silent type, but the 1-ton robot was making a lot of noise during its harrowing Red Planet touchdown on Aug. 5. Curiosity phoned home throughout its daring and unprecedented landing sequence that night, giving its nervous handlers step-by-step status and health updates. The European Space Agency's Mars Express orbiter recorded some of this chatter, and now we can hear what Curiosity had to say. Sort of. ESA scientists have processed Curiosity's radio signals, shifting them to frequencies the human ear can hear.

ESA's Mars Express has returned strong evidence for an ocean once covering part of Mars. Using radar, it has detected sediments reminiscent of an ocean floor within the boundaries of previously identified, ancient shorelines on Mars. The MARSIS radar was deployed in 2005 and has been collecting data ever since. Jérémie Mouginot, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG) and the University of California, Irvine, and colleagues have analysed more than two years of data and found that the northern plains are covered in low-density material. "We interpret these as sedimentary deposits, maybe ice-rich," says Dr Mouginot. "It is a strong new indication that there was once an ocean here."

Anomalies in the operation of the solid-state mass memory system on board Mars Express have caused science observations to be temporarily halted. A technical work-around is being investigated that will enable the resumption of a number of observations and should evolve into a long-term solution. In mid-August, Mars Express autonomously entered safe mode, an operational mode designed to safeguard both the spacecraft itself and its instrument payload in the event of faults or errors. The cause of entering the safe mode was a complex combination of events relating to reading from and writing to memory modules in the Solid-State Mass Memory (SSMM) system. This is used to store data acquired by the instruments and housekeeping data from the spacecraft's subsystems, prior to its transmission to Earth, and is also used to store commands for the spacecraft that have been received from the ground stations, while awaiting execution.

ESA’s Mars Express has spotted a rare case of a crater once filled by a lake, revealed by the presence of a delta. The delta is an ancient fan-shaped deposit of dark sediments, laid down in water. It is a reminder of Mars’ past, wetter climate. The delta is in the Eberswalde crater, in the southern highlands of Mars. The 65 km-diameter crater is visible as a semi-circle on the right of the image and was formed more than 3.7 billion years ago when an asteroid hit the planet.

ESA’s Mars Express has returned new views of pedestal craters in the Red Planet’s eastern Arabia Terra. Craters are perhaps the quintessential planetary geological feature. So much so that early planetary geologists expended a lot of effort to understand them. You could say they put craters on a pedestal. This latest image of Mars shows how the Red Planet does it in reality. Craters are the result of impacts by asteroids, comets and meteorites. In a pedestal crater, the surrounding terrain is covered by pulverised rock thrown out of the crater. This material creates a platform or pedestal around the crater often with steep cliffs, and is usually rich in volatile materials such as water and ice.

Without doubt, Phobos is the grooviest moon of the Solar System. By that I mean, that it is covered with a multitude of parallel grooves. Initially, it was thought that these markings radiated away from the largest crater on Phobos. Called Stickney, the crater has a diameter of 9 km and is the most obvious feature of the moon’s pockmarked surface. Some thought that the grooves were debris ejected across Phobos during Stickney’s creation. In other words, they were similar to the bright rays of material seen emanating from some craters on the Moon. Most thought that they were fractures in the moon, opened up by the mighty impact. But these hypotheses were based upon an incomplete picture of Phobos – literally and metaphorically.

Unfortunately for anyone looking to terraform Mars, a new study shows that powerful waves of solar wind periodically strip the Red Planet of its atmosphere. Scientists had known for years that Mars has atmosphere troubles, but only by analyzing new data from he Mars Express spacecraft were they able to identify the special double solar waves as the specific cause. Double solar waves are a rare phenomenon that result when the Sun emits waves of differing speeds. If a fast wave follows a slow wave, the fast wave crashes into the back of the slow one, rolling them both up into a super-charged double wave. Scientists were able to correlate Martian atmosphere loss, as measured by the the Mars Express spacecraft, with records of double radiation waves in 2007 and 2008 taken by the Advanced Composition Explorer spacecraft. According to the study, one third of Martian atmosphere loss occurs during these waves, which are only present 15 percent of the time.

Fresh imagery from Europe's Mars Express orbiter shows the Martian moon Phobos in sharp, 3-D detail. This isn't the first time Phobos has gotten its close-up, but interest in the irregular moon is rising - in part because it's increasingly seen as a steppingstone for Mars-bound astronauts. Last month, NASA shifted its focus from sending humans back to the moon to a "flexible path" that includes the moons of Mars as potential destinations. The idea is that low-gravity locales such as Phobos (and Mars' other moon, Deimos) should be easier to get to because they're more accommodating for landing and ascent.

Images from the recent flyby of Phobos, on 7 March 2010, are released today. The images show Mars’ rocky moon in exquisite detail, with a resolution of just 4.4 metres per pixel. They show the proposed landing sites for the forthcoming Phobos-Grunt mission. ESA's Mars Express spacecraft orbits the Red Planet in a highly elliptical, polar orbit that brings it close to Phobos every five months. It is the only spacecraft currently in orbit around Mars whose orbit reaches far enough from the planet to provide a close-up view of Phobos.

The European Mars Express (Mex) probe has made its closest flyby of the Martian moon Phobos, passing just 67km (42 miles) from its surface. No manmade object has ever been so near to the natural satellite. The approach is one of a series being made by Mex as it seeks to understand the origin of the moon. Previous flybys have indicated that Phobos has an extremely low density, suggesting that its surface probably hides many large interior voids. Scientists suspect the moon is simply a collection of planetary rubble that coalesced around the Red Planet sometime after its formation.

A European space probe is on track for a close encounter with the Martian moon Phobos, an odd, potato-shaped satellite -- origins unknown -- that may be partly hollow. Mapping Phobos' gravity is among scientists' top priorities when the Mars Express spacecraft soars as close as 50 kilometers (31 miles) above the moon Wednesday night. Previous passes of Phobos by Mars Express have raised as many questions as they've answered. For example, calculations of the moon's density led scientists to the surprising theory that parts of Phobos may be hollow. Minute changes in the probe's flight path -- tracked by a radio signal -- as it passes over the moon Wednesday will be closely monitored in an attempt to correlate Phobos' gravitational tugs with internal structural variations.

On 3 March 2010 Mars Express will make its closest ever approach to Phobos, the larger of the two Martian moons. During a series of flybys, spanning six weeks, all seven instruments onboard Mars Express will be utilised to study Phobos. The close approach provides a first opportunity to perform a unique gravity experiment that may reveal the distribution of mass within this intriguing moon.