Jeff Morris
6.6K views | +0 today
Follow
Jeff Morris
Science, Security, and anything of interest
Curated by Jeff Morris
Your new post is loading...
Your new post is loading...
Rescooped by Jeff Morris from Amazing Science
Scoop.it!

Still hot inside the Moon: Tidal heating in the deepest part of the lunar mantle

Still hot inside the Moon: Tidal heating in the deepest part of the lunar mantle | Jeff Morris | Scoop.it

An international research team, led by Dr. Yuji Harada from Planetary Science Institute, China University of Geosciences, has found that there is an extremely soft layer deep inside the Moon and that heat is effectively generated in the layer by the gravity of the Earth. These results were derived by comparing the deformation of the Moon as precisely measured by Kaguya (SELENE, Selenological and Engineering Explorer) and other probes with theoretically calculated estimates. These findings suggest that the interior of the Moon has not yet cooled and hardened, and also that it is still being warmed by the effect of the Earth on the Moon. This research provides a chance to reconsider how both the Earth and the Moon have been evolving since their births through mutual influence until now.

 

When it comes to clarifying how a celestial body like a planet or a natural satellite is born and grows, it is necessary to know as precisely as possible its internal structure and thermal state. How can we know the internal structure of a celestial body far away from us? We can get clues about its internal structure and state by thoroughly investigating how its shape changes due to external forces. The shape of a celestial body being changed by the gravitational force of another body is called tide. For example, the ocean tide on the Earth is one tidal phenomenon caused by the gravitational force between the Moon and the Sun, and the Earth. Sea water is so deformable that its displacement can be easily observed. How much a celestial body can be deformed by tidal force, in this way, depends on its internal structure, and especially on the hardness of its interior. Conversely, it means that observing the degree of deformation enables us to learn about the interior, which is normally not directly visible to the naked eye. The Moon is no exception; we can learn about the interior of our natural satellite from its deformation caused by the tidal force of the Earth. The deformation has already been well known through several geodetic observations. However, models of the internal structure of the Moon as derived from past research could not account for the deformation precisely observed by the above lunar exploration programs.


Via Dr. Stefan Gruenwald
more...
No comment yet.
Rescooped by Jeff Morris from Amazing Science
Scoop.it!

How to put mirrors in space big enough to see continents and forests on exoplanets

How to put mirrors in space big enough to see continents and forests on exoplanets | Jeff Morris | Scoop.it

Shooting a laser at polystyrene beads, scientists have made a mirror that is held together by light. The creation could be a step towards putting ultra-light mirrors in space that would be big enough to see continents and forests on planets orbiting far-off stars.

 

Current space telescopes have limited vision because is it costly and complicated to send large, heavy mirrors into orbit. The mirror on NASA's premiere planet hunter, the Kepler space telescope, is just 1.4 metres across and cannot see planets directly. Instead Kepler spots the tiny changes in brightness when a world crosses in front of its host star.

 

When NASA's James Webb Space Telescope launches in a few years, it will carry the largest mirror yet into space: a 6.5-metre behemoth made of 18 interlocking segments. To fit into the launch vehicle, the mirror itself will have to be folded up and then unfolded in space.

 

Jean-Marc Fournier of the Swiss Federal Institute of Technology in Lausanne, Switzerland, and his colleagues have revived an old idea for building much larger mirrors by exploiting the force produced when laser beams hit tiny particles. Previous work has used this force to make optical tweezers, which can trap and manipulate a few particles at a time.

 

In 1979, astronomer Antoine Labeyrie, now at the Collège de France in Paris, suggested that the force could also trap a collection of particles into a flat plane to form a mirror. In theory, shooting two lasers at a central point should cause their optical forces to interfere, creating a stable region where particles line up to make a two-dimensional surface.

 

Such a mirror would be exceptionally light, relatively inexpensive and even self-repairing, as any particles knocked out by micro-meteors, which are constantly zipping through space, would simply be replaced by others nearby.

 

With funding from NASA's Institute for Advanced Concepts, Fournier's team took a first step towards this goal. They used a single laser to trap 150 micrometre-sized polystyrene beads against a sheet of glass (pictured). Light would normally bounce off a single bead in all directions, but grouping them together produces a flat reflective surface that acts exactly like a mirror, says Fournier.

 

To prove the mirror worked, the team shot light through a transparent ruler, so that it bounced off the beads and onto a detector. The resulting picture was murky, but they were able to make out an image of the number 8 on the ruler, which wasn't possible when the beads were removed from the glass.


Via Dr. Stefan Gruenwald
more...
No comment yet.
Rescooped by Jeff Morris from Amazing Science
Scoop.it!

Could Lichen from Antarctica survive on Mars?

Could Lichen from Antarctica survive on Mars? | Jeff Morris | Scoop.it

Humans cannot hope to survive life on Mars without plenty of protection from the surface radiation, freezing night temperatures and dust storms on the red planet. So they could be excused for marveling at humble Antarctic lichen that has shown itself capable of going beyond survival and adapting to life in simulated Martian conditions.

The mere feat of surviving temperatures as low as -51 degrees C and enduring a radiation bombardment during a 34-day experiment might seem like an accomplishment by itself. But the lichen, a symbiotic mass of fungi and algae, also proved it could adapt physiologically to living a normal life in such harsh Martian conditions—as long as the lichen lived under "protected" conditions shielded from much of the radiation within "micro-niches" such as cracks in the Martian soil or rocks.

The lichen chosen for the experiment, called P. chlorophanum, has proven itself a survival champion even before the Mars simulation. Researchers removed lichen samples for testing from its home atop the rocky Black Ridge in Antarctica's North Victoria Land—a frozen, dry landscape not unlike that of many places on Mars.

 

Similar lichens have shown they can survive exposure to the vacuum of space as well as space radiation. The past experiments conducted by the European Space Agency aboard Russian FOTON satellites and the International Space Station included de Vera as a co-investigator.

 

The latest Mars simulation experiment did not try to simulate the Martian dust storms that can blanket the entire planet for a month. But de Vera points out that lichen can survive in a resting state for thousands of years on Earth while covered with dust, snow or ice.


Via Dr. Stefan Gruenwald
more...
Carlos Garcia Pando's comment, January 20, 2014 3:14 AM
Regarding the blanketing due to dust storms, this lichen survives 6 months of dark night every year here on Earth,