Tag Archives: hydrology

Even more awesome images of Pluto released!

I know, I know, we’ve spoiled you with awesome photos of Pluto already, this couldn’t possibly surprise you, could it? Well, I dare say NASA has done it again – this new batch of New Horizons images is absolutely breathtaking.

Majestic Mountains and Frozen Plains: Just 15 minutes after its closest approach to Pluto on July 14, 2015, NASA’s New Horizons spacecraft looked back toward the sun and captured this near-sunset view of the rugged, icy mountains and flat ice plains extending to Pluto’s horizon. The smooth expanse of the informally named Sputnik Planum (right) is flanked to the west (left) by rugged mountains up to 11,000 feet (3,500 meters) high. Credits: NASA/JHUAPL/SwRI)

New Horizons is an interplanetary space probe launched to study Pluto and the outer areas of our solar system. On July 14, 2015 11:49 UTC (07:49 EDT), it flew 12,500 km (7,800 mi) above the surface of Pluto, making it the first human spacecraft to study the small planetoid. It took so many photos and analyzed so much information that NASA will be downloading it for about a year.

These oblique images offer an unprecedented look into Pluto’s landscapes, with dramatic backlighting from the Sun. The scene above measures 780 miles (1,250 kilometers) across. It almost looks like taken from a hot air balloon.

“This image really makes you feel you are there, at Pluto, surveying the landscape for yourself,” said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute, Boulder, Colorado. “But this image is also a scientific bonanza, revealing new details about Pluto’s atmosphere, mountains, glaciers and plains.”

Pluto’s Majestic Mountains, Frozen Plains and Foggy Hazes: Just 15 minutes after its closest approach to Pluto on July 14, 2015, NASA’s New Horizons spacecraft looked back toward the sun and captured this near-sunset view of the rugged, icy mountains and flat ice plains extending to Pluto’s horizon. Credits: NASA/JHUAPL/SwRI

But it’s not just pretty pictures – New Horizons images offer a trove of valuable information about Pluto. Along with the previous photos, NASA now believe Pluto has an Earth-like hydrological cycle, but one which involves soft and exotic ices like nitrogen, instead of water.

“In addition to being visually stunning, these low-lying hazes hint at the weather changing from day to day on Pluto, just like it does here on Earth,” said Will Grundy, lead of the New Horizons Composition team from Lowell Observatory, Flagstaff, Arizona.

Pluto’s ‘Heart’: Sputnik Planum is the informal name of the smooth, light-bulb shaped region on the left of this composite of several New Horizons images of Pluto. The brilliantly white upland region to the right may be coated by nitrogen ice that has been transported through the atmosphere from the surface of Sputnik Planum, and deposited on these uplands. The box shows the location of the glacier detail images below.
Credits: NASA/JHUAPL/SwRI

 

Valley Glaciers on Pluto: Ice (probably frozen nitrogen) that appears to have accumulated on the uplands on the right side of this 390-mile (630-kilometer) wide image is draining from Pluto’s mountains onto the informally named Sputnik Planum through the 2- to 5-mile (3- to 8- kilometer) wide valleys indicated by the red arrows. The flow front of the ice moving into Sputnik Planum is outlined by the blue arrows. The origin of the ridges and pits on the right side of the image remains uncertain.
Credits: NASA/JHUAPL/SwRI

 

This comes as a surprise because NASA wasn’t expecting to find liquid or frozen nitrogen at all – let alone a hydrological cycle.

“We did not expect to find hints of a nitrogen-based glacial cycle on Pluto operating in the frigid conditions of the outer solar system,” said Alan Howard, a member of the mission’s Geology, Geophysics and Imaging team from the University of Virginia, Charlottesville. “Driven by dim sunlight, this would be directly comparable to the hydrological cycle that feeds ice caps on Earth, where water is evaporated from the oceans, falls as snow, and returns to the seas through glacial flow.Pluto is surprisingly Earth-like in this regard,” added Stern, “and no one predicted it.”

The next step is to study the photos and determine, from the morphology what kind of geological and erosional features are present on Pluto. They’ve already identified some interesting features.

ntricate Valley Glaciers on Pluto: This image covers the same region as the image above, but is re-projected from the oblique, backlit view shown in the new crescent image of Pluto. The backlighting highlights the intricate flow lines on the glaciers. The flow front of the ice moving into the informally named Sputnik Planum is outlined by the blue arrows. The origin of the ridges and pits on the right side of the image remains uncertain. This image is 390 miles (630 kilometers) across.
Credits: NASA/JHUAPL/SwRI

 

Water on Mars

The Martian Polygons – An evidence for former Seafloors?

Intricate polygons on Mars could be a clear indication of a wet past for the Red Planet. Most crater floor polygons have diameters ranging from 15 to 350 m, and it’s still not clear how and why they appeared – though one theory seems to be gaining ground: the idea of former lake beds.

Water on Mars

Image 1. Typical crater floor polygons. [A] CTX (a 6 meter/pixel camera onboard the Mars Reconnaissance Orbiter, P16_007372_2474).of a 14 km‐sized impact crater

Polygons are some of the most common features at high latitudes on Mars. They have been observed by both lander and orbiting spacecraft. They range in size from 2 m all the way up to 10 km, and there is still an ongoing debate regarding their formation. Proposed mechanisms include thermal contraction, desiccation, volcanic, and tectonic processes; the polygons also bear similar resemblance to polygons observed on Earth, which took shape on the seafloor.

In 2000, an analytical model based on fracture mechanics (El Maarry et al., 2010) showed that through thermal changes alone (no water), the maximum fracture spacing attainable is 75 meters, with more probable values revolving around 20 meters – so this is clearly not the cause here. Also, no exact tectonic processes which can cause such formations have been identified – so the only plausible possibility left is a former sea floor.

On Earth, polygon-shaped areas, with the edges formed by faults, are common in fine-grained deep-sea sediments. Some of the best examples of these polygon-fault areas are found in the North Sea and the Norwegian Sea. We know this because the areas have been thoroughly surveyed through seismic techniques for offshore oil and gas deposits. While they are diverse and intricate, all polygons seem to have one thing in common – form in a common environment: sediments made up of fine-grained clays in ocean basins that are deeper than 500 meters, and when these sediments are only shallowly buried by younger sediments. The slope angle of the seafloor also plays a crucial role: when the slope is very gentle (or non existent), the shape of the polygons tends to remain unchanged. However, when there is some positive or negative topography, the shapes are often altered or broken down.

So if this is indeed the case on Mars (and there’s little reason why it shouldn’t be), it seems pretty clear that we’re dealing not only with a water body, but with a water body which was at least half a kilometer deep. Furthermore, the variation of crater floor polygons sizes with location can be indicative of different hydrologic environments. So not only was there likely water on Mars – but it was likely a big and complex system.

Climate Change Threatens Drinking Water

sea level rise


As sea levels rise coastal communities could lose up to 50 percent more of their fresh water supplies than previously thought, according to a new study from Ohio State University. This is not just bad news for them; it is a warning for everybody.Studies have shown how altwater will intrude into fresh water aquifers, given the sea level rise predicted by the Intergovernmental Panel on Climate Change (IPCC). The results were very discouraging; sea level could rise as much as 23 inches, flooding coasts worldwide in the next 100. This argues with what they believed before that as saltwater moved inland, it would penetrate underground only as far as it did above ground.

But the research they have made obviously shows that when saltwater and fresh water meet, they mix in complex ways, depending on the texture of the sand along the coastline and things are not as easy as they seemed. Just as saltwater, brackish water is not safe to drink because it causes dehydration. Graduate student Jun Mizuno said that “Almost 40 percent of the world population lives in coastal areas, less than 60 kilometers from the shoreline,” and These regions may face loss of freshwater resources more than we originally thought.”.

The further increase in sea level makes things even harder to predict. But what is certain is that water is getting scarcer with every passing year. “In order to obtain cheap water for everybody, we need to use groundwater, river water, or lake water,” Ibaraki said. “But all those waters are disappearing due to several factors –including an increase in demand and climate change.”. We could desalinate saltwater but that would be very expensive.