December 18, 2017

15.05.11: Gravity Probe B Scores Another One for Einstein.

One of the Gravity Probe B Spheroids…(Credit: NASA/Don Harley)

A mission decades in the making has come to fruition. Recently, scientists have announced the results of the Gravity Probe B experiment. This mission was conceived way back in 1963 and had to await the birth of entirely new technologies before even reaching orbit. [Read more...]

AstroEvent: The Best Appearance of Mercury in 2011.

Mercury+Jupiter in the dusk. (Photo by Author).

If you’ve never seen the inner-most world of our solar system, this week is your chance. On Tuesday, March 22nd, the planet Mercury reaches a greatest elongation of 19 degrees east of the Sun.  Due to the varying angle of our ecliptic during different times of the year coupled with an eccentricity of 0.21 for Mercury’s orbit, not all apparitions of the innermost world are equal. [Read more...]

15.06.10: Found: Lunokhod 1.

NASA has located an old friend on the lunar surface; Lunokhod 1, which landed on the lunar surface in 1970 and fell silent after 11 months of service. A Soviet unmanned rover, Lunokhod 1 delivered some first rate science. Remember, the Apollo astronauts stayed on the lunar surface for a period of time equivalent to a weekend camping trip. With its old school tech, Lunokhod 1 is decidedly steam punk in appearance. Fans of this space will also remember its sister rover Lunokhod 2, purchased by Richard Gariott for $68,500 in 1993. Both were imaged and recovered by the Lunar Reconnaissance Orbiter recently, and now scientists are recruiting the rovers to conduct science once again.  Lunokhod 1 was equipped with corner cube prisms, which reflect laser light back at exactly the direction that it came from. On April 22nd of this year, scientists at the Apache Point observatory in New Mexico fired (you always “fire” lasers!) laser pulses of light via the 3.5 meter telescope and were surprised with the results; more than 2,000 photons were successfully gathered on the first try. In fact, the reflectors on Lunokhod 1 are now brighter than on Lunokhod 2, which may be a scientific mystery in and of itself. Scientists hope to use studies in how the Moon moves through space to search out any potential kinks in General Relativity. That’s right; in the true spirit of science, Relativity (and Gravity, for that matter) is still being run through the mill, over a century later. Thus far, reality, as always, looks to be firmly on the side of Einstein, with the help of a now stationary defunct Soviet-era rover!

27.03.10- Modeling Black Holes.

Researchers are calling in the big guns in the quest to understanding black holes. Specifically, scientists at the Rochester Institute of Technology are using time on some of the fastest and most powerful computers in use to model and predict the activity of super massive black holes. But these aren’t your ordinary off the shelf PCs; their laboratory New Horizons machine is a computer cluster of 85 nodes with 4 processors that is capable of passing data at a rate of 10 gigabytes per second. Try that on your family Mac book! Further grants totaling $2.9 million will enable the team to hone their theoretical models over the next 3 years on ever faster machines. “It’s a thrilling time to study black holes, ” states center director Manuela Campanelli. If predictions match observations, these models may also serve as the best proof yet of Einstein’s General Theory of Relativity…more to come!

22.10.09: Thank Relativity that We’re Here!

The next time you’re studying the Lorentz equation or are forced to account for Relativity on your Buzzard Ramjet trip to Sirius, thank Einstein that we’re here at all! Scientists Jacques Laskar and Mickael Gastineau at the Paris Observatory have been modeling orbital dynamics in our solar system and have come up with some “disturbing” results. It has long been known that Jupiter has a shepherding effect on the inner solar system, smoothing out planetary orbits while ejecting or sweeping up incoming debris. However, if you model the planetary orbits taking into account only classic Newtonian motion, the odds that Mercury goes out of whack in the Sun’s 10 billion year odd life span are about 60%. Throw in Einstein, and the effect shrinks to less than 1%. A careening Mercury would be a bad thing; if it impacted Venus, we would get showered with debris over a million year span, and if it hit us, well, it would just be a bad day. The best thing it could do is harmlessly impact the Sun. Even a near miss with the Earth could drastically alter our orbit, not to mention tinker with our stabilizing Moon. Fortunately, the tiny tweak that the Sun’s gravitational well gives Mercury’s eccentric orbit via General Relativity assures that a resonance keyhole with Jupiter’s orbit probably won’t happen. Keep in mind, we’re talking tiny effects that pile up over billions of years… every time an asteroid whizzes by, we launch a Space Shuttle, or LeBron performs a slam dunk, the Earth gets a tiny push. Over billions of years, tiny forces do add up (ever heard of the Butterfly Effect?) This is why astronomers cannot predict the positions of planets more than a million or so years into the future. Incidentally, the precession of Mercury’s orbit still stands as one of the great observational proofs of Relativity. One also wonders if such a perturbation might have been the fate of Theia, the Mars sized impactor that has been hypothesized to have struck a prehistoric Earth and created our Moon. So the next time you see gravity bend light at relativistic speeds, thank Einstein for protecting our home planet Earth!