Universe Today Podcast

In this week's life Q&A, I explain why we don't send animals to space any more, why I don't think we'll ever travel faster than the speed of light, and how graveyard orbits work.

On Sunday, January 19th, 2020, SpaceX launched a Falcon 9 rocket carrying its newly designed Crew Dragon spacecraft. 84 seconds into flight, at the moment of maximum aerodynamic pressure, the capsule fired its eight SuperDraco thrusters, detaching from the top of the rocket and flying ahead.

Moments after, the Falcon 9 rocket exploded in midair, destroying a completely good rocket, but the capsule was completely safe, jettisoning its trunk and landing gently in the ocean a few minutes later.

Nobody was on board the spacecraft, just a couple of test dummies, but this test proved that in the case of an emergency during the ascent stage fo the mission, Crew Dragon would be able to carry its astronaut crew to safety.

In 2006, astronomers spotted the telltale sign of a supernova detonating in the galaxy NGC 1260, located about 240 million light-years away in the constellation of Perseus. As telescopes around the world turned their collective light-gathering power on the expanding explosion designated as SN 2006gy, they realized they were seeing something very unusual.

This clearly wasn’t a regular supernova. It grew to be 100 times brighter than the typical stellar explosion and lasted much much longer.

More than a decade after that cosmic explosion, astronomers finally think they know what series of events led to the release of this much energy, now called a superluminous supernova. A red giant ate a white dwarf. An event so rare it probably accounts for only 1 in 1000 supernovae.

Whenever I talk about the search for life in the Universe and its emphasis on water, I get comments that scientists aren’t being creative enough. Why does life rely on water? Couldn’t there be lifeforms which are completely different from life on Earth? Isn’t that the textbook definition of alien?

Astrobiologists have only scratched the surface in their search for life in the Universe, and they’re going after the low-hanging fruit. Since life on Earth can be found wherever there’s water, why not check out the water on other worlds? If that doesn’t pan out, then they’ll expand the search.

But it’s possible there are aliens living right here on Earth among us, in a shadow biosphere, we just haven’t detected them yet.

In this week's questions show, I wonder whether any aliens out there would be nice to us or try to wipe us out. What would be their motivations? Why are planets turning in the wrong direction? Would Betelgeuse generate gravitational waves?

In 2015, scientists discovered the telltale signal from ripples of spacetime sweeping over the Earth. It was the very first direct detection of gravitational waves, generated by the merger of two massive black holes 1.3 billion light-years away.

This discovery was the culmination of decades of research and construction of huge instruments called interferometers to detect the warping of spacetime caused by gravitational waves.

Today, the most advanced detectors, the LIGO/VIRGO collaboration, have turned up over 50 gravitational wave discoveries - on average one every week - allowing astronomers to perceive the Universe in a completely different way.

What new gravitational wave instruments are in the works, and what does the future hold for this relatively new field of study?

In this week's questions show, I explain why it doesn't make sense to send a microscope to Mars, how we could use a black hole to see a reflection of Earth and see dinosaurs, and why we don't just send a solar sail down to the Sun.

This week I'm joined by Professor Greg Eghigian, from Penn State University to talk about the history of UFO sightings and claims of alien contact.

You can read a recent essay by Dr. Eghigian on Smithsonian's Air and Space Magazine:

https://www.airspacemag.com/space/year-ufos-180973965/

And learn more about his work here:
https://history.la.psu.edu/directory/gae2

We’ve now passed the 50th anniversary of the Apollo 11 landing, and all eyes are back on the Moon. NASA is planning to return to the Moon by 2024 with its Artemis mission, the Chinese have put the Moon firmly in their plans for space exploration, and even SpaceX thinks the Moon is the perfect destination to test out the capabilities of its Starship.

But what can you do with the Moon? Refuel spacecraft with resources drawn from the lunar regolith? Mine its helium 3 for your fusion reactors? Build a lunar amusement park?

In fact, the far side of the Moon might make one of the best platforms we have for radio telescopes. One side of the Moon is completely blocked from Earth’s constantly increasing radio traffic, giving it the perfect view to the most sensitive radio signals in the Universe.

On Monday, January 6th, 2020, another SpaceX Falcon 9 blasted off from Cape Canaveral, carrying another 60 Starlink internet communications satellites, bringing the full size of the constellation to 180. With just three launches, SpaceX becomes the largest satellite operator in the world.

But the company is just getting started. They’re planning to do this again every couple of weeks during 2020, bringing the total number of satellites in the constellation to about 1440, which is enough to provide high-speed internet services to the United States and parts of Canada.

Shortly after launch, as the satellites are raising their altitude, they’re clearly visible to the eye as they streak across the sky in a close train.

Astronomers aren’t happy.