Month: August 2018

Enlarge / Fermi's view of the galaxy's core. (credit: NASA/DOE/Fermi LAT/D. Finkbeiner et al.)

Not so long ago, I attended a general physics conference where a lot of people were very excited about the Fermi Large Area Telescope. Fermi observed high-energy radiation from the galactic center and found an excess that was hard to explain. Might this be a long-awaited sign of dark matter? Early calculations seemed promising.

Now, it seems that the signal might due to pulsars and not dark matter.

What did Fermi see?

The Fermi telescope watches the sky for gamma rays. These are photons with energies in the range of 10 million electron Volts (eV) up to about 300 billion eV. For comparison sake, light in the visible range is less than 10eV, while a standard X-Ray machine in a hospital has photons with an energy of about 2,000eV. So gamma rays are photons that pack a serious punch.

Making fun of The Meg might be more trouble than it's worth. There's no hype for this adaptation of a schlocky 1997 novel about a scientifically unsound super-shark. So what if Jason Statham (Crank, Transporter) got caught up in an unfortunate film? Every summer has its low-stakes stinker.

But we would be doing summer moviegoers a disservice to not warn them of exactly what to expect, should you use a shark movie as an excuse to sit in a theater's air conditioning on a hot day. In particular, anybody with even the slightest appreciation for science, logic, or sound research practices needs to brace their butts for how baffling The Meg turns out to be.

Dunh-dunh-dunnnnh

Enlarge / At NASA's Goddard Space Flight Center, the Parker Solar Probe is lowered into the 40-foot-tall thermal vacuum chamber for testing. (credit: NASA)

Six decades have passed since a University of Chicago physicist pondered why the tail of a comet, no matter the direction it traveled, always pointed away from the Sun. From this and other observations made by astronomers, Eugene Parker theorized that there must be some kind of stream of particles flowing away from the Sun. He called this the "solar wind."

It turns out that such a stream of charged particles does exist, a moving plasma of electrons, protons, and other particles that varies in density and speed. Over time, as observations mounted, astronomers moved from a position of skepticism about Parker's solar-wind idea to one of acceptance. Then, nearly 30 years ago, scientists launched their first mission, Ulysses, to make direct measurements of the phenomenon.

Astronomers have since come to realize the profound importance of this solar wind for our planet and the rest of the Solar System. For example, we now know that a few hundred million years after its formation, the early solar wind accelerated ions in the upper Martian atmosphere to an escape velocity, stripping the young planet of much of its atmosphere over time.

Enlarge (credit: Aurich Lawson/United Launch Alliance)

Welcome to Edition 1.12 of the Rocket Report! This week we have all kinds of stories about small rockets, the scoop on a Texas rocket company back from the dead, and some commercial crew launch dates that we may believe. Or maybe not.

As always, we welcome reader submissions, and if you don't want to miss an issue, please subscribe using the box below (the form will not appear on AMP-enabled versions of the site). Each report will include information on small-, medium-, and heavy-lift rockets as well as a quick look ahead at the next three launches on the calendar.

New report quantifies surge in small rockets. In an updated report on the state of the small-satellite launch industry, Carlos Niederstrasser quantifies the increase in potential small launch vehicle contenders, defined as rockets capable of carrying up to 1000kg to low-Earth orbit. The growth has been remarkable. "The total number of efforts we are tracking... has increased from a mere 31 in 2015 to over 101 in 2018," he writes.