Mars, Earth, sun line up perfectly in sky this weekend

“In both instances, the blue moon is a calendar oddity caused by the 19-year Metonic cycle”.

Mars once featured a vast ocean that covered its northern hemisphere.

They point to satellite data suggesting a major redistribution of sediments over a large region at the edge of the Red Planet’s northern lowlands.

They occur because about every two years Earth’s orbit catches up to Mars’ orbit, aligning the sun, Earth, and Mars in a straight line, so that Mars and the sun are on “opposing” sides of Earth.

That’s the theory, anyway. It is an unusual phenomenon but would be analogous to what is being suggested – albeit on a much larger scale – for Mars. But very little observational data actually exists.

Saturday, stargazers will be able to see this season’s rare extra full moon and then Sunday the red planet Mars will shine more brightly than any star in the night sky.

The chances are good that microbial life existed on Mars long ago, and sending astronauts to the Red Planet is the best way to find the evidence, NASA’s chief scientist said. There’s solid evidence for these two tsunami events, but that doesn’t preclude more events yet to be discovered. They discovered traces of a former ocean-though not exactly where one might expect.

These mega-tsunamis probably numbered in the dozens over hundreds of millions of years, but the study, published in Nature’s Scientific Reports, focused on two that happened a few million years apart.

The findings also explain why scientists can’t seem to find continuous shorelines: The tsunamis totally buried them. Frigid temperatures were freezing Mars’ oceans. They were caused by meteor impacts that caused craters 30 kilometres wide. In 2003, for example, Mars came within 34.65 million miles (55.76 million km) of Earth – the closest the two planets had been in 60,000 years, ESA officials said. But by this stage in Martian history, the climate had become considerably colder. In that period of time, the planet’s water began freezing and the shorelines receded.

This second tsunami resulted in the formation of rounded lobes of ice – a portion of the ice sheet that projects from the main area. “It formed widespread backwash channels to carry the water back to the ocean”, said Alberto Fairén, Cornell University visiting scientist in astronomy and principal investigator at the Center of Astrobiology, Madrid, in a press release. “Under certain circumstances liquid water has been found on Mars“.

Researchers involved with the new study, however, realized one thing could account for the discrepancy: Mega-tsunamis.Alexis RodriguezIn this elevation map, red regions (right) show ancient tsunami deposits.

“In spite of the extremely cold and dry global climatic conditions, the early Martian ocean likely had a briny composition that allowed it to remain in liquid form for as long as several tens of millions of years”.

“The astrobiological implications are enormous”, Rodriguez told Gizmodo. The team used computer models to indicate that such tsunamis could have been produced by large asteroid strikes, producing waves with an average height of more than 160 feet, with the largest reaching almost 400 feet high.