Nasa's Curiosity rover on Mars

Whale rock on Mar

One explanation for Whale is a static model, and the other is a dynamic time model," explains Prof Gupta, from Imperial College London. The latter may be right, and that would be really exciting because it is telling us something about the water budget changing. But the important thing is that we are seeing the interface between the rivers and the lakes. Whale is a marker for us that they existed at the same time, and that really gives us confidence in particular that we are seeing ancient lake deposits. At the point when researchers first saw it in pictures came back from Nasa's Curiosity meanderer on Mars, they truly weren't certain what to make of it.  Sitting glad on top of a heap of finely layered mudstones, this coarser sandstone outcrop appeared a bit strange. Along these lines, the group charged the robot to drive here and there for a bit, to take a gander at some other tempting geography in Gale Crater.  Be that as it may, every time Curiosity returned for another look, the head-scratching proceeded. 

What was Whale Rock, and why was it there? 

This week the group discharged its considered elucidation of the silt saw in Gale amid over a year's wandering by Curiosity. The report, distributed in Science magazine, portrays how these silt are likely the remaining parts of streams and waterways that streamed over the hole's edge and over its floor, moderating and spreading into deltas that eventually nourished a progression of diligent lakes.  Furthermore, Whale Rock, it turns out, has something of a featuring part in this story.  The stone gives us certainty that we have our model right," says Sanjeev Gupta, a senior researcher on the mission.  Quite a bit of what is in the Science paper was initially talked about last December in a mission-group video chat with journalists.  The interceding months have seen the hard join expected to corral all the confirmation into the sort of contentions that will pass summon in an associate assessed insightful diary. Furthermore, those contentions are compelling.The coarser rock that the robot saw out on the hole floor, close to its arrival point, offered approach to logically littler grained rocks as it drove south, closer to Gale's commanding focal mountain, Aeolus Mons (Mount Sharp). What's more, these dunking strata finished in a thick gathering of finely layered mudstones. 

The covers are what you would expect when a great many plumes of silt heartbeats into a lake, loses vitality and settles out of the standing water to develop the bed. What's more, Whale? It sits above 10m or thereabouts of these stunning mudstones, fairly settled in them, and lens-formed. Whale has covers, as well, however its bigger grains are those of a sandstone, which means its testimony surroundings was more vivacious. Its dregs were conveyed in undulating water. All that head-scratching has presumed that Whale denote the physical edge of a lake - the interface with the delta that was sustaining it. There are two ways it could have formed.One understanding is entirely direct: it is the delta stores really infringing into the lake, filling little chasms.  The second probability is more included: it could be the place the lake has retreated sooner or later, and the sustaining stream from the delta has chopped down and dissolved another channel. The stream's own residue have then moved into this channel yet have later been encased by the better muds when the lake level has return up. 

In any case, you are taking a gander at a stone recording of occasions that happened, maybe over only a couple of hours and days, more than three billion years prior on another planet. Curiosity's big drive to Mount Sharp saw it climb up through 75m of sediments. What we know of deposition rates in water environments on Earth suggests this stratigraphy took anywhere from 10,000 right up to 10 million years to accumulate. And if even higher sediments at Mount Sharp (these have not been directly investigated by Curiosity but look the same from satellite imagery) are taken into account, this deposition time becomes even longer.For decades, researchers have wondered if the flat, northern lowlands could have held an ocean during Mars' early history. The latest Curiosity results are re-igniting interest in this idea, says John Grotzinger, the lead author on this week's paper and the former project scientist on Curiosity. The simplest explanation is that there probably was a body of water out there that was creating an environment at the dichotomy (the boundary between Mars' northern lowlands and southern highlands), and at Gale Crater it supplied water moisture to the northern rim that flowed into the crater basin," the Caltech professor speculated.Either all of these geological observations, which seem to be adding up in the same direction, are incorrect (and we always have to be open to that possibility); or we're simply missing something. Perhaps, we don't have the greenhouse gas inventory and climate conditions for early Mars correct yet.