They also looked at whether craters made by the comets hitting the surface could excavate enough nitrogen — but that would require a very deep layer
of nitrogen ice at the surface, which is not proven.
If Pluto were a completely smooth sphere, it would have either a permanent swath
of nitrogen ice at the equator or seasonal snow caps at its poles.
Not exact matches
On Pluto, a slurry
of nitrogen and water
ice melted by subsurface heat stands in for lava, the team suggests, freezing solid once it is exposed
at the surface.
The new images,
at resolutions
of about 80 meters per pixel, show a striking shoreline, where smooth plains
of nitrogen ice from Pluto's «heart» rub up against water
ice mountains several kilometers high.
The jumbled - up rubble
at the base
of the
ice mountains helps confirm team members» theories that the mountains are, in fact, giant icebergs that have moved around on more plastic layers
of nitrogen ice below.
Using sediment gathered from the ocean floor in different areas
of the world, the researchers were able to confirm that as the
ice sheets started melting and the climate warmed up
at the end
of the last
ice age, 18,000 years ago, the marine
nitrogen cycle started to accelerate.
A McGill - led international research team has now completed the first global study
of changes that occurred in a crucial component
of ocean chemistry, the
nitrogen cycle,
at the end
of the last
ice age.
Data reported by NASA's New Horizons New Horizons mission to the Pluto system shows unusual terrain in this region, which features a large deposit
of nitrogen ice with a pattern
of polygons that are thickest
at their centers and dip
at their edges.
Engineer Barbara Wyslouzil
of Ohio State University and colleagues made the cubed
ice by shooting
nitrogen and water vapor through nozzles
at supersonic speeds.
There is probably water -
ice at depth on Pluto, but the surface
ice is a mixture
of frozen methane, ethane, carbon monoxide and
nitrogen.
Instead, they appear bright white, more like the regions
of Pluto covered in
nitrogen ice, according to work presented
at an American Astronomical Society meeting on 17 October by Will Grundy
at the Lowell Observatory and Orkan M. Umurhan
at the SETI Institute.
A team
of Buck scientists will be on hand to make instant liquid
nitrogen ice cream — a major hit
at last year's event.
Now, if you have all this very cold, nearly freezing water surrounding these
ice caps, sucking up carbon dioxide out
of the polar atmosphere,
at nearly the highest possible rate, 30 times faster than oxygen, and 70 times faster than
nitrogen, doesn't it stand to reason that the air that remains might just have a lot less carbon dioxide in it than the atmosphere across the rest
of the planet?
Two chefs combine foods in unusual ways in this extension
of their cooking school, where the waiters know as much about the food as the chefs (a decided advantage, as some
of the items may need explaining)-- fillet cooked in a dishwasher, lamb shank cooked slowly in an electric blanket, or liquid
nitrogen boiled
ice - cream (
at your table).
To make the link, Hastings, with Julia Jarvis and Eric Steig from the Department
of Earth and Space Sciences
at the University
of Washington, examined
at high resolution for the first time two isotopes
of nitrogen found in nitrates in a Greenland
ice core.
Scientific confidence
of the occurrence
of climate change include, for example, that over
at least the last 50 years there have been increases in the atmospheric concentration
of CO2; increased
nitrogen and soot (black carbon) deposition; changes in the surface heat and moisture fluxes over land; increases in lower tropospheric and upper ocean temperatures and ocean heat content; the elevation
of sea level; and a large decrease in summer Arctic sea
ice coverage and a modest increase in Antarctic sea
ice coverage.