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Mars, Viking Orbiter Mosaic JB1960
The center of Mars is at latitude 30 degrees north, longitude 270 degrees. NASA's Viking Mission to Mars was composed of two spacecraft, Viking 1 and Viking 2, each consisting of an orbiter and a lander. The primary mission objectives were to obtain high resolution images of the Martian surface, characterize the structure and composition of the atmosphere and surface, and search for evidence of life. The results from the Viking experiments give our most complete view of Mars to date. Volcanoes, lava plains, immense canyons, cratered areas, wind-formed features, and evidence of surface water are apparent in the Orbiter images. The planet appears to be divisible into two main regions, northern low plains and southern cratered highlands. Superimposed on these regions are the Tharsis and Elysium bulges, which are high-standing volcanic areas, and Valles Marineris, a system of giant canyons near the equator. The surface material at both landing sites can best be characterized as iron-rich clay. Measured temperatures at the landing sites ranged from 150 to 250 K, with a variation over a given day of 35 to 50 K. Seasonal dust storms, pressure changes, and transport of atmospheric gases between the polar caps were observed. The biology experiment produced no evidence of life at either landing site. June 1998. View more images of Mars at ScienceSource.com
In the news: "Insulin levels wax and wane daily" by Tina Hesman Saey Science News February 22, 2013 BU6284 Islets of Langerhorns The islets of Langerhans are groups of specialized cells in the
pancreas that make and secrete hormones. There are five types of cells
in an islet: alpha cells (blue) that make glucagon, which raises the
level of glucose (sugar) in the blood; beta cells (yellow -- shown in
crossection) that make insulin; delta cells (purple) that make
somatostatin which inhibits the release of numerous other hormones in
the body; and PP cells and D1 cells, about which little is known.
Insulin molecules are shown as green spheres; glaucagon molecules as
blue spheres and glucose molecules as gray spheres. Insulin and glucagon
can be seen entering the blood stream through the walls of capillaries.
Degeneration of the insulin-producing beta cells is the main cause of
type I (insulin-dependent) diabetes mellitus. Labeled. Credit:
Carol and Mike Werner / Science…
In the last decade or so, we’ve experienced giant tornados, damaging wildfires, flood-inducing rainstorms, fatal heat waves, and droughts destroying crops and livestock like never before.
At the same time the polar jet stream, a westerly wind generated by solar radiation and the corollas effect (a phenomenon that creates our weather), has been behaving in unprecedented ways. Scientists believe this is not a coincidence, rather it is related.Stock Images of Climate Change, Extreme Weather and the Jet Stream
Normally, the jet stream travels either in a straight line or undulates in waves called Rossby waves. Rossby waves bring warm air northward and cold air southward. This can create a temporary heat wave or a rainstorm.
The jet stream is powered by the temperature differential between the cold arctic air and the warmer air in the lower latitudes. As global warming continues to warm the arctic air, the jet stream is losing its power. The Rossby waves have become larger, expanding mu…
Scientists recently came one step closer to figuring out how to stop mosquitoes from biting us.
Mosquitos have plagued humans and other warm-blooded mammals for eons. Aside from ruining an otherwise beautiful summer evening with their itchy bites, they transmit some of the worst diseases known to man. Malaria, zika, yellow fever, dengue, West Nile Virus, encephalitis, and chikungunya are some of the deadliest.RF & RM Stock Images of Mosquitos
Many of these have no cure and may cause congenital disabilities or death.
In the United States West Nile virus, eastern equine encephalitis, western equine encephalitis, St. Louis encephalitis, La Crosse encephalitis, dengue, and yellow fever are all transmitted by mosquitoes.
The good news is that scientists continue to discover precisely how mosquitoes find us? It will help us figure out how to stop them from biting us.
The recent finding confirms that it is the acids in our sweat that attract them. Genetically altered mosquitoes that co…