UFO'S of UAP'S, ASTRONOMIE, RUIMTEVAART, ARCHEOLOGIE, OUDHEIDKUNDE, SF-SNUFJES EN ANDERE ESOTERISCHE WETENSCHAPPEN

Credit: ESA

Beyond Earth, Mars is the most habitable planet in the solar system — but that doesn't mean we can simply move there and expect to live off the land.

Though the surface of Mars is more barren (and a lot more toxic) than the most arid desert on Earth, NASA has uncovered a vast underground supply of water ice that may, someday, be an oasis for future Mars explorers.

Key to our future Mars settlers' survival will be the utilization of resources already on the Red Planet, so the necessity of landing future Mars explorers near a known water resource is a no-brainer. Water isn't only a requirement for keeping astronauts alive, it's needed for fuel production and would sustain any burgeoning Martian agriculture. Put simply, unless we find Mars water and understand how to access it, our Mars colonization dreams are over. But the discovery of a vast reservoir of subsurface water ice by an orbiting NASA Mars satellite could represent a game-changer for the future of Mars colonization.

"This deposit is probably more accessible than most water ice on Mars, because it is at a relatively low latitude and it lies in a flat, smooth area where landing a spacecraft would be easier than at some of the other areas with buried ice," said Jack Holt, of the University of Texas, in a statement.

The deposit was found beneath the famous Utopia Planitia, the Martian plain where NASA's Viking 2 robotic lander set down in 1976. Using data from NASA's Mars Reconnaissance Orbiter's ground-penetrating Shallow Radar (SHARAD), researchers discovered the huge slab of ice, ranging from 260 feet (80 meters) to 560 feet (170 meters) thick covering an area larger than the state of New Mexico. The deposit is 50-85 percent water ice mixed with dust and rocks.

Utopia is located halfway between Mars' north pole and equator, a region where water ice cannot currently persist on the surface. It is thought that the ice accumulated in the location when the planet was a lot more tilted than it is now. The Red Planet's tilt varies wildly over the course of its approximate 120,000 year cycles; its current axial tilt is around 25 degrees, but it can tilt as much as 60 degrees. This wild range causes significant climatic changes that forced the formation of ice from the poles to lower latitudes in the past.

"This deposit probably formed as snowfall accumulating into an ice sheet mixed with dust during a period in Mars history when the planet's axis was more tilted than it is today," said Cassie Stuurman, of the Institute for Geophysics at the University of Texas, Austin, and lead author of a study published in the journal Geophysical Research Letters.

The subsurface reservoir at Utopia represents a climatic record of these climatic shifts, protected by a 1-10-meter-thick layer of Mars rock and regolith — Martian "soil" which is composed of the ground-up dusty remains of eons of meteorite impacts. This thin surface layer means the first human Mars explorers could relatively easily drill into the water ice deposit, either mining chunks of water ice for processing, or directly heating the layer and pumping out liquid water.

Of course, the presence of water ice will lead to the speculation of the possibility of Mars life. Could there have been pockets of slushy liquid water underground that allowed microbial life gain a foothold?

"Where water ice has been around for a long time, we just don't know whether there could have been enough liquid water at some point for supporting microbial life," Holt added.

Utopia has long been suspected as a location where water ice is hiding. Polygonal surface features that are commonly seen in the Canadian Arctic are an indicator of subsurface ice are also present in Utopia. However, this is the first time that the presence of subsurface ice has been confirmed in the region. There is also evidence of ancient river channels in the region (pictured top) where it is thought that subsurface ice melted and flowed.

"The ice deposits in Utopia Planitia aren't just an exploration resource, they're also one of the most accessible climate change records on Mars," said co-author Joe Levy of the University of Texas. "We don't understand fully why ice has built up in some areas of the Martian surface and not in others. Sampling and using this ice with a future mission could help keep astronauts alive, while also helping them unlock the secrets of Martian ice ages."

Originally published on Seeker.

For a generation, the Hubble Space Telescope has been exposing the universe's deepest, darkest secrets. From imaging the volcanoes of Jupiter's moon Io, to watching the dramatic breakup of comets, imaging baby galaxies, and helping to nail down the universe's age, its data has been instrumental in today's understanding of the cosmos near and far.

But it's an old telescope, unmaintained since the last space shuttle mission visited in 2009. While the observatory is in excellent health today, it's expected to stop collecting data sometime in the 2020s. What will we lose when the telescope finally dies?

NASA is quick to point out that the James Webb Space Telescope, expected to launch in 2018, will enhance Hubble's capabilities in many ways. But for the telescope's higher resolution and ability to peer back to the very early days of the universe, there is one key thing it doesn't have: ultraviolet capabilities. (It also will lack some of Hubble's fine spectral resolution, and ability to observe a special spectral line called H-alpha that is useful for nebulae and stars.)

Astronomers are being urged to submit as many UV proposals to Hubble as possible because once it dies, there are no immediate plans to launch a successor. (Astronomers could then pull from the archive as needed in future decades.) Earth's atmosphere filters out UV, which is great for protecting life, but bad for UV astronomy, so it needs to be done from space. Astronomers say they don't think another UV telescope will fly until the 2030s, at the earliest.

"For example, one of the big topics that we're going to look at in star and planet formation is the accretion of gas on to young, newly forming stars or planets," said Adam Kraus, an astronomer at the University of Texas at Austin. He explained that as gas falls on to budding stars and planets, they radiate most of their energy in the blue and ultraviolet wavelengths. Webb won't be able to see this as Hubble does, he told Seeker.

**The James Webb Space Telescope (pictured here during a mirror inspection) will enhance Hubble's observations in many areas, but it lacks in ultraviolet capabilities.**
**Credit: NASA/MSFC/David Higginbotham**

NASA's Jane Rigby, the deputy project scientist for Webb's operations, points out that the new telescope is designed to do science that Hubble can't. Webb has seven times more collecting area and also works at near absolute zero (the coldest temperature possible). Hubble works at room temperature, so it can't see as well in the infrared. Webb will see into dusty places where stars are forming, or galaxies that have been deeply "redshifted" (with spectral lines moving towards the red end of the spectrum) due to cosmic expansion.

Luckily for astronomers, it's expected that Hubble's and Webb's time in space will overlap. Hubble has a rich archive of observations that Webb could spend time looking at, including the famous "deep fields" of young galaxies. This type of work will be Webb's "bread and butter", Rigby said.

There's also the potential to make stereoscopic or "3D" images of several objects, since Hubble (in low Earth orbit) will be a million miles away from Webb, further out in space. At the Space Telescope Science Institute (STScI), which manages Hubble observations, some astronomers suggest images could be taken of nearby objects.

"You could see Saturn's rings sticking out of the page, Mars looking like a globe, or Jupiter and its moons moving," Joel Green, a project scientist at STScI, told Seeker. "There's a few scientific reasons, too. You might want to look at how cloud structures change in 3D, or how an impact happens in 3D."

Another possibility, he added, would be looking at a star explosion (or supernova) and from the distance between the telescopes, finding out where the explosion is coming from and examining certain features of the explosion.

Hubble's ultraviolet capabilities are not replicated in any telescope now, or in the near future. Here, possible water plumes on Europa (disclosed earlier this year) are imaged using Hubble's ultraviolet filters.
**Credit: NASA/ESA/W. Sparks (STScI)/USGS Astrogeology Science Center**

Other observatories are planned after Webb. One is the Wide Field Infrared Survey Telescope (WFIRST), which would use Hubble-class hardware that has a wider field of view. Its specialty would be dark energy and exoplanets. Another is the Transiting Exoplanet Survey Satellite (TESS), which would look at planets passing in front of the brightest stars in our sky. These likely would get going in the 2020s, if funding for the missions is fully approved.

But the next generation is still being worked out. NASA draws heavily from the National Science Foundation's Decadal Survey when planning its missions. Right now, proposals are being formulated to present to members of the next decadal survey, which will be released in 2020.

This will be the battleground for where UV astronomy is determined for the near future. NASA is planning to do up to four mission concept studies to present for the 2020 Decadal Survey, including a mission called the Large Ultraviolet/Optical/Infrared Surveyor (LUVOIR). As the name implies, it's supposed to be capable of observing in several wavelengths.

If it flies, it would examine protoplanetary disks, look for and image black holes, map the Milky Way and even look at nearby exoplanet atmospheres for signs of habitability. But it is competing against several other mission concepts, including one focused on infrared (Far-IR Surveyor), one for X-rays (X-ray surveyor) and a more modest UV and optical observer called HabEx. HabEx may use a special, separate shield to filter out a star's light for direct planet observations, which would be a first in astronomy.

An artist's concept of the Habitable Exoplanet Imaging Mission, which is still on the drawing board and not approved for funding. This is a possible successor to some of Hubble's capabilities, on top of the current James Webb Space Telescope.
**Credit: JPL/NASA**

"We're very hopeful that the national community in 2020 will fund one of these things and go forward," said Karl Stapelfeldt, the chief scientist of NASA's exoplanet science program. The aim is not only to be able to look at Earth-like planets around nearby stars, he said, but to study the rest of the universe as well.

There are other UV telescopes being proposed, such as Advanced Technology Large Aperture Space Telescope or ATLAST (which was considered in the last decadal survey) and the High Definition Space Telescope (HDST). This makes for a dizzying array of options and ideas for anybody trying to think ahead for the next generation of space telescopes.

While this is all being discussed, however, Webb is getting ready for launch. NASA's Rigby said she is greatly looking forward to the science that the telescope will provide.

"When you look the way Webb is designed, it is building on the legacy of Hubble," she said. "It's very much being built to do the things Hubble can't, because the things Hubble can do it's done so exquisitely... it's optimized in a totally different direction from Hubble, because Hubble has given us a legacy over 25 years within the range of its capabilities."

Originally published on Seeker.