At first glance, it looks uncannily like Martians trying to use morse code. However, in fact this bizarre series of dots and dashes forms a huge area of dunes on the surface of the red planet. Experts believe the limited amount of sand in the area has led to the strange patterns forming as Martian winds blow. The stunning image was taken in the Hagal Dune field just south of Mars' north polar cap. Experts believe the limited amount of sand in the area led to the strange patterns forming as winds blow.
Mars harbors a mysterious kind of dune-like structure that's unlike anything seen on Earth, a new study reports. These unusual sandy ripples might yield insights about how Mars has evolved over time from a potentially habitable world to the harsh, dry planet we know today, researchers added. On Earth, wind blowing over sand causes the formation of either small ripples a few inches to a foot long to large dunes that can stretch for miles. Collectively, these structures are known as bedforms. Now, by analyzing high-resolution images taken by NASA's Mars Reconnaissance Orbiter and Mars rover Curiosity, scientists have discovered a kind of bedform intermediate in size between the tiny ripples and big dunes seen on Earth's landmasses.
Wind blowing over sand on Earth produces decimeter-wavelength ripples and hundred-meter– to kilometer-wavelength dunes: bedforms of two distinct size modes. Observations from the Mars Science Laboratory Curiosity rover and the Mars Reconnaissance Orbiter reveal that Mars hosts a third stable wind-driven bedform, with meter-scale wavelengths. These bedforms are spatially uniform in size and typically have asymmetric profiles with angle-of-repose lee slopes and sinuous crest lines, making them unlike terrestrial wind ripples. Rather, these structures resemble fluid-drag ripples, which on Earth include water-worked current ripples, but on Mars instead form by wind because of the higher kinematic viscosity of the low-density atmosphere. A reevaluation of the wind-deposited strata in the Burns formation (about 3.7 billion years old or younger) identifies potential wind-drag ripple stratification formed under a thin atmosphere.
Modern-day Mars has two moons, the tiny potato-shaped lands of Phobos and Deimos. But at one time the red planet was circled by many more, and one of these drew the tiny satellites into orbit, according to a new study. The new paper solves the mystery that has plagued scientists for years - the question of how Mars came to have two moons and not just one, like us. A couple of hours after, a disk of debris formed (Middle) A large moon rapidly emerged from the disk close to the planet. It had originally been thought that Mars' moons were asteroids that had been captured by the planet's gravity, but this idea was overtaken by the theory that a giant impact created the satellites.
Investigators with NASA's Curiosity rover are exploring dark sand dunes on Mars and have discovered structures thought to be unlike any on Earth: ripples spaced about 3 meters apart, intermediate in size between the little ripples and big dunes found on both planets. Scientists aren't sure how they form, but they think the density of the thin martian atmosphere plays a role in shaping them. If they can find the fossilized ripples in rocks hardened from ancient dunes, they could glean clues about the thicker atmosphere of early Mars. The result is one of the highlights of a campaign to investigate the dunes in Gale Crater that gird the mountain the rover is trying to get to. For several weeks this past December and January, the rover stopped to take pictures, make wind measurements, and sift sand into its chemical analysis instrument.