In what has truly turned out to be a momentous occasion in astrophysics, today scientists announced the first-ever direct observation of gravitational waves by the Laser Interferometer Gravitational-wave Observatory (LIGO) experiment, which consists of two enormous detector facilities located in Louisiana and Washington state and an international consortium of thousands of researchers.
First predicted by Albert Einstein in 1915, gravitational waves are the “ripples” in the fabric of space-time created by exceptionally turbulent and powerful cosmic events. Physicists have accepted their existence for decades and in recent years have even observed their effects, but only with the incredible sensitivity of the NSF-funded advanced LIGO instrument has their direct detection been made possible.
“This was truly a scientific moon shot, and we did it. We landed on the moon.”
– David Reitze, Executive Director of LIGO
Back in December of 2001, Saturn’s moon Titan passed in front of two background stars (called an “occultation”) from the point of view of the Hale Telescope at Palomar Observatory. Astronomers used the incredible resolving ability of the 5-meter telescope’s adaptive optics to watch the event, which revealed the diffraction of the stars’ light through Titan’s dense atmosphere as well as allowing them to measure the moon’s stratospheric winds. Check it out above!
Video credit: A. Bouchez, M. Brown, M. Troy et al./Caltech
NASA’s Wide-field Infrared Survey Explorer – WISE – has recently finished a survey of small bodies in our solar system. The survey mission, called NEOWISE (for Near Earth Objects), used WISE’s infrared-imaging capabilities to identify 20 new comets and more than 33,000 main-belt asteroids. WISE also spotted 134 near-Earth objects – asteroids or comets that come within 28 million miles of Earth’s orbit.