Sustained hypersonic flight above speeds of Mach 5 by vehicles using air-breathing, jet-fuel-powered engines could become achievable within the next dozen years.
Successful recent ground tests of jet-fueled, ramjet/scramjet demonstrator engines by Pratt & Whitney Rocketdyne and Aerojet represent important progress toward flight-testing of three separate hypersonic-vehicle programs.
Women can be allergic to sex with men, but doctors are finding women can overcome this allergy through regular sex combined with treatments derived from semen.
"It's really a very rare condition, but it does happen," says David Resnick at New YorkPresbyterianHospital. Semen allergy symptoms can include itching, burning and swelling in the genitals. In the most severe cases, hives or swelling might appear elsewhere on the body and the woman might experience difficulty breathing.
"Typically symptoms occur within 30 minutes of intercourse, but in rare cases it may be hours or even days later," Resnick explained.
One study from the University of Cincinnati of 1,073 women who sought information on semen allergy concerning their symptoms found 130 had the allergy. In some women, the reaction occurs only with one partner while others are allergic to all partners.
Phobos seems to be composed of the same materials as Deimos, but for some reason, the moon has a seriously low density. So low that in the 1960's Russian planetary scientists suggested that the moon was hollow, and might be an artificial satellite...
In 1988 the Soviet Union launched two probes to study Mars and its two moons Phobos and Deimos. Unlike most other Russian missions around the solar system, the Phobos I and II missions were done with some cooperation with the United States, which contributed the use of the Deep Space radio telescope network.
The missions were to provide the first close look at Phobos and Deimos, and hopefully answer the question as to why these two moons are unlike anything else in the solar system.
Using ESO's Very Large Telescope Interferometer, astronomers have discovered a disc of silicate dust at the heart of the Ant Nebula. The disc seems, however, too lightweight to explain how the nebula got its unique ant-like shape, with three nested pairs of bipolar lobes.