Alien Life Discovered Soon?

Many astronomers involved in the search for extraterrestrial life and the discovery of planets beyond our solar system seem to be coalescing around a prediction that alien life will be found within twenty years. There is a difference in how the big event will come about, however. Some say SETI will succeed in finding a signal from an extraterrestrial civilization, while others say the find will more likely be of simple life forms on Mars, Europa, or Enceladus.

The more will learn about the cosmos, the more it seems to be that life is likely common throughout the universe. Still, twenty years is quite the prediction. The fact that several astronomers are willing to stand by that publicly may bespeak a quiet, considered confidence-- or it may mean that, once again, the universe will prove more complex than humans imagine.

Close Call

For just the second time, astronauts aboard ISS had to retreat to Soyuz capsules as a piece of space debris roughly two inches across threatened to rip a hole in ISS yesterday. That might not sound like a huge problem, but mass that size traveling at 17,500 miles per hour packs quite a punch. Had it hit and caused major damage, the astronauts would have attempted to return to Earth. NASA estimates that, in fact, the piece came within roughly a thousand feet of the station. While NASA generally has a couple days or more warning of such a potential problem, this time it only had fourteen hours.

The incident emphasizes the dangers posed by space debris in low Earth orbit to continuing operations there. Thousands of pieces of stuff that big are zipping around, and that number is only growing as more nations and corporations reach into space; the number of smaller, still dangerous bits is in the tens of thousands.

Space agencies and aerospace corporations are working on the problem by trying to make rocket operations less messy, and by finding ways to de-orbit debris already there. The solutions to the problem are slow in coming, however. There is a small but non-zero chance that we will lose a spacewalking astronaut-- and possibly ISS itself-- to collisions with space debris by 2020.

New USAF Satellite

The U. S. Air Force is launching a new, sophisticated reconnaissance satellite tonight. The satellite is designed to markedly increase the warfighting capability of U. S. forces.

The U. S. is increasing dependent on satellites. American military power gets an edge over its adversaries through intelligence and communications abilities using satellites. Satellites also provide a wide range of services that strengthen the U. S. economy. The need to protect such assets will, at some point, shape U. S. space policy. Protecting satellites by giving them defensive capabilities would be expensive and add complexity to an already complex craft. Therefore, likely American policy moving forward will include support for efforts to deal with dangerous debris in orbit, as well as trying to restrict the development and deployment of anti-satellite technology.

Testing SpaceShipTwo

Test flights of Virgin Galactic's SpaceShipTwo continue to progress smoothly, systematically expanding the envelope within which the suborbital spacecraft has successfully flown. June 14 and 15 saw test flights on consecutive days-- an important demonstration for a system that will have to fly regularly once operational to be commercially viable.

VG plans to continue the test flight program the rest of this year, adding powered flights of SpaceShipTwo perhaps by October. So far, all test flights have been glides, checking out systems and flight characteristics. The flight program will slow in July, allowing engineers of Scaled Composites, builder of the craft, to thoroughly analyze the data collected up to that point.

Genesis

In 2001, NASA launched its Genesis probe to capture and bring to Earth particles of the solar wind. Genesis crashed in Utah in 2004, but enough of the pristine material survived to support two separate scientific studies.

Both studies suggest Earth was not formed from the original disk of gas and dust that orbited the Sun, as has been assumed. Differences in the abundances of isotopes of nitrogen and oxygen in the Earth and the solar wind suggest there was an intermediate step that changed the composition of the planetary disk before Earth formed.

Scientists have theories about what may have happened, but further work will be needed to work out exactly what caused the change.

Flying Saucers

Today marks the 64th anniversary of pilot Kenneth Arnold's sighting of nine strange ships flying in formation in the area of Mount Rainier, the extinct volcano that towers over Seattle. His report of the incident touched off the modern UFO era.

Of course, early on, they were called "flying saucers" after Arnold's description of the flight characteristics of the objects he saw; "UFO" came into usage much later. After Arnold's report, a wave of similar reports swept the nation, leading up to the Roswell Incident about two weeks later. Since then, UFO reports, for whatever reason, have tended to come in waves.

Today, we can explain virtually all UFO reports of the first few decades of the era in Earthly terms. We also know the CIA encouraged UFO mania as a cover for the flights of its exotic spy planes. Still, there is a small core of reports that defy explanation. Often, that's because the information in the reports is not specific and detailed enough to allow hypotheses to be formed and tested. That will always be an issue for science in the field, however. There are also complex reports by seemingly capable people, sometimes with (claimed) physical evidence. What to make of those?

Salty Enceladus

Scientists using data from NASA's Cassini spacecraft have found important amounts of salt in the geyser spray of Saturn's moon, Enceladus. They found small amounts of salt in Saturn's wispy E-Ring, which is maintained by Enceladus' geyser eruptions, and higher amounts on the moon's surface just outside the geysers-- precisely the situation to be expected if the salt was erupting out of the geysers from deep within.

On Earth, ocean water is salty because of the interaction between water and the rock surrounding it, and scientists are assuming the same holds on Enceladus. Salt, therefore, is further evidence that an ocean of liquid water exists under the Enceladus ice shell, which in turn strengthens the case for life possibly existing at that moon.