Cassini Data Suggests Blocks of Hydrocarbon Floating on Titan's Lakes
It's not exactly icing on a cake, but it could be icing on a lake. A new
paper by scientists on NASA's Cassini mission finds that blocks of
hydrocarbon ice might decorate the surface of existing lakes and seas of
liquid hydrocarbon on Saturn's moon Titan. The presence of ice floes
might explain some of the mixed readings Cassini has seen in the
reflectivity of the surfaces of lakes on Titan.
"One of the most intriguing questions about these lakes and seas is
whether they might host an exotic form of life," said Jonathan Lunine, a
paper co-author and Cassini interdisciplinary Titan scientist at
Cornell University, Ithaca, N.Y. "And the formation of floating
hydrocarbon ice will provide an opportunity for interesting chemistry
along the boundary between liquid and solid, a boundary that may have
been important in the origin of terrestrial life."
A pair of large sunspots has rotated into view over
the sun's eastern limb. The two dark cores, collectively
known as AR1654, are 4 times bigger than
Earth.
NASA's Solar Dynamics Observatory
took this picture of the twins during the early
hours of Jan. 10th
The two sunspots are presently
crackling with low-level C-flares. Much stronger
eruptions are possible.
Priceless thousand year old statue is first carving of a human in a meteorite
It sounds like an artifact from an Indiana Jones film; a 1,000 year-old ancient Buddhist statue which was first recovered by a Nazi expedition in 1938 has been analysed by scientists and has been found to be carved from a meteorite. The findings, published in Meteoritics and Planetary Science, reveal the priceless statue to be a rare ataxite class of meteorite.
ESA’s Herschel space observatory made new observations of asteroid Apophis as it approached Earth this weekend. The data shows the asteroid to be bigger than first estimated, and less reflective.
Herschel’s three-colour view of asteroid Apophis.
Catalogued as asteroid (99942) Apophis (previously 2004 MN4), it is often nicknamed ‘the doomsday asteroid’ in popular media, after initial observations made after its discovery in 2004 gave it a 2.7% chance of striking Earth in April 2029.
With additional data, however, an impact in 2029 was soon ruled out, although the asteroid will pass within 36 000 km of Earth’s surface, closer even than the orbits of geostationary satellites.
Asteroid Apophis will have its nearest
approach to planet Earth today, January 9. Viewers can watch the live
streaming of the asteroid flyby at the website Slooh.com. The online
sky-watching service will also provide footages from other
observatories all over the world.
The future for Apophis on Friday, April
13 of 2029 includes an approach to Earth no closer than 29,470 km
(18,300 miles, or 5.6 Earth radii from the center, or 4.6 Earth-radii
from the surface) over the mid-Atlantic, appearing to the naked eye
as a moderately bright point of light moving rapidly across the sky.
Depending on its mechanical nature, it could experience shape or
spin-state alteration due to tidal forces caused by Earth's gravity
field.
This is within the distance of Earth's geosynchronous
satellites. However, because Apophis will pass interior to the
positions of these satellites at closest approach, in a plane
inclined at 40 degrees to the Earth's equator and passing outside the
equatorial geosynchronous zone when crossing the equatorial plane, it
does not threaten the satellites in that heavily populated region.
Using criteria developed in this research, new measurements
on this approach,2013 will likely confirm that in 2036 Apophis will
quietly pass more than 49 million km (30.5 million miles; 0.32 AU)
from Earth on Easter Sunday of that year (April 13).
Asteroid Apophis' radar observations
will greatly help in improving the asteroid's orbit analyses as well
as identifying the impact chances. "Due to the proximity of its
orbit to Earth, Apophis is being considered as a potential target for
both robotic and crewed spacecraft missions," NASA's JPL further
stated.
A large sunspot emerging is crackling with C-class solar flares and, based on its size, could be capable of even stronger eruptions.
So far the sunspot is relatively quiet,
producing only a smattering of low-level C-class
solar flares. We will know more about AR1654's flare-producing
potential in the days ahead as the sunspot turns
toward Earth.
If there are a lot of sunspots, the magnetic field is most stressed, and the Sun
is at its most active. The magnetic flux may get so stressed that it may
"reconnect" with opposite polarities, releasing huge amounts of energy as
flares.
Coronal mass ejections may be unleashed from these flare events, sending
hot solar plasma into space. If directed at the Earth, these CMEs can cause
damage to satellites, astronauts, even whole power grids on the ground.
Small asteroid 2012 DA14 will make an extremely close approach on
February 15, 2013. It will pass by Earth at distance of about 27,000 km
(17,000 miles/no closer than 0.000181 AU) from the center of the Earth; within about 3.5 Earth radii of the Earth’s surface.
This near-Earth asteroid was discovered on February 22, 2012 by
LaSagra Observatory in the mountains of Andalusia in southern
Spain. Asteroid 2012 DA14 is thought to be about 45 meters in diameter
and his estimated mass about 130,000 metric tons.
The Asteroid 2012 DA14 will pass below distance where many commercial
satellites are flying. It will pass inside the geosynchronous satellite
ring, located about 35,800 km above the equator. The nominal pass will
be 0.00023 AU (34,000 km; 21,000 miles) from the center-point of the
Earth.
Asteroid 2012 DA14 will pass by Earth at distance of about 27,000 km
(17,000 mile) from the center of the Earth. Just for comparison –
400-meters wide asteroid YU 55 passed 320,000 kilometers (200,000
miles) from Earth on November 8, 2011. Even closer flyby of asteroid 2011 MD last June was closer than DA14 will at a distance of only 12,070 km (7,500 miles).
For now, the orbit of 2012 DA14 is such that it will not crash into
Earth for the foreseeable future. It rates 0 (No Hazard) on the Torino
scale.
With such a close approach to Earth, our planet’s gravity will change
its future path and rise a chance of future impact. There is an
estimated cumulative 0.033% risk (1 in 3,030) of 2012 DA14 impacting
Earth sometime between 2026 and 2069.
Some scientist believe that similar-in-size object hit Tunguska in
1918. If it were to strike the Earth, it is estimated that it would
produce the equivalent of 2.4 megatons of TNT. The Tunguska event has
been estimated at 3−20 megatons.
So, the world did not end Friday because of an asteroid blast or any
of the other calamities imagined to be predicted by the ancient Mayan
calendar.But some say a serious asteroid strike is just a matter of time, and we should be ready.
For
evidence of what might come, see the 1908 “Tunguska event” in Siberia,
said Ed Lu, a former shuttle and International Space Station astronaut
who heads the nonprofit B612 Foundation (the name references the
asteroid home from “The Little Prince.”)
The most intense solar maximum in fifty years is
coming. The prediction comes from a team led by Mausumi Dikpati of the
National Center for Atmospheric Research (NCAR). "The next sunspot cycle
will be 30% to 50% stronger than the previous one," she says. If
correct, the years ahead could produce a burst of solar activity second
only to the historic Solar Max of 1958.
Active region 1158 let loose with an X2.2 flare late on February 15, the largest flare since Dec. 2006
credit:NASA/SDO
That
was a solar maximum. The Space Age was just beginning: Sputnik was
launched in Oct. 1957 and Explorer 1 (the first US satellite) in Jan.
1958. In 1958 you couldn't tell that a solar storm was underway by
looking at the bars on your cell phone; cell phones didn't exist. Even
so, people knew something big was happening when Northern Lights were
sighted three times in Mexico. A similar maximum now would be
noticed by its effect on cell phones, GPS, weather satellites and many
other modern technologies.
But today a similar solar maximum would cause major problems in our technological addicted societies
NASA's Mars rover Curiosity dug up five scoops of sand from a patch
nicknamed "Rocknest." A suite of instruments called SAM analyzed Martian
soil samples, but the findings have not yet been released.
Scientists working on NASA's six-wheeled rover on Mars have a problem. But it's a good problem.
They
have some exciting new results from one of the rover's instruments. On
the one hand, they'd like to tell everybody what they found, but on the
other, they have to wait because they want to make sure their results
are not just some fluke or error in their instrument.
It's
a bind scientists frequently find themselves in, because by their
nature, scientists like to share their results. At the same time,
they're cautious because no one likes to make a big announcement and
then have to say "never mind."
The exciting
results are coming from an instrument in the rover called SAM.
"We're
getting data from SAM as we sit here and speak, and the data looks
really interesting," John Grotzinger, the principal investigator for the
rover mission, says during my visit last week to his office at NASA's
Jet Propulsion Laboratory in Pasadena, Calif. That's where data from SAM
first arrive on Earth. "The science team is busily chewing away on it
as it comes down," says Grotzinger.
