Interacting Galaxy

The 2023 Partial (Annular) Solar Eclipse as seen from Nevada // Brian Fulda

Please, forecast, be right about tomorrow night.

(For where we live, that's clear).

We were extremely fortunate to have Jocelyn Bell Burnell as a virtual guest in a women in science class! She was a pleasure to listen to and continues to be an inspiration.

Navigating Deep Space by Starlight

On August 6, 1967, astrophysicist Jocelyn Bell Burnell noticed a blip in her radio telescope data. And then another. Eventually, Bell Burnell figured out that these blips, or pulses, were not from people or machines.

The blips were constant. There was something in space that was pulsing in a regular pattern, and Bell Burnell figured out that it was a pulsar: a rapidly spinning neutron star emitting beams of light. Neutron stars are superdense objects created when a massive star dies. Not only are they dense, but neutron stars can also spin really fast! Every star we observe spins, and due to a property called angular momentum, as a collapsing star gets smaller and denser, it spins faster. It’s like how ice skaters spin faster as they bring their arms closer to their bodies and make the space that they take up smaller.

The pulses of light coming from these whirling stars are like the beacons spinning at the tops of lighthouses that help sailors safely approach the shore. As the pulsar spins, beams of radio waves (and other types of light) are swept out into the universe with each turn. The light appears and disappears from our view each time the star rotates.

After decades of studying pulsars, astronomers wondered—could they serve as cosmic beacons to help future space explorers navigate the universe? To see if it could work, scientists needed to do some testing!

First, it was important to gather more data. NASA’s NICER, or Neutron star Interior Composition Explorer, is a telescope that was installed aboard the International Space Station in 2017. Its goal is to find out things about neutron stars like their sizes and densities, using an array of 56 special X-ray concentrators and sensitive detectors to capture and measure pulsars’ light.

But how can we use these X-ray pulses as navigational tools? Enter SEXTANT, or Station Explorer for X-ray Timing and Navigation Technology. If NICER was your phone, SEXTANT would be like an app on it.  

During the first few years of NICER’s observations, SEXTANT created an on-board navigation system using NICER’s pulsar data. It worked by measuring the consistent timing between each pulsar’s pulses to map a set of cosmic beacons.

When calculating position or location, extremely accurate timekeeping is essential. We usually rely on atomic clocks, which use the predictable fluctuations of atoms to tick away the seconds. These atomic clocks can be located on the ground or in space, like the ones on GPS satellites. However, our GPS system only works on or close to Earth, and onboard atomic clocks can be expensive and heavy. Using pulsar observations instead could give us free and reliable “clocks” for navigation. During its experiment, SEXTANT was able to successfully determine the space station’s orbital position!

We can calculate distances using the time taken for a signal to travel between two objects to determine a spacecraft’s approximate location relative to those objects. However, we would need to observe more pulsars to pinpoint a more exact location of a spacecraft. As SEXTANT gathered signals from multiple pulsars, it could more accurately derive its position in space.

So, imagine you are an astronaut on a lengthy journey to the outer solar system. You could use the technology developed by SEXTANT to help plot your course. Since pulsars are reliable and consistent in their spins, you wouldn’t need Wi-Fi or cell service to figure out where you were in relation to your destination. The pulsar-based navigation data could even help you figure out your ETA!

None of these missions or experiments would be possible without Jocelyn Bell Burnell’s keen eye for an odd spot in her radio data decades ago, which set the stage for the idea to use spinning neutron stars as a celestial GPS. Her contribution to the field of astrophysics laid the groundwork for research benefitting the people of the future, who yearn to sail amongst the stars.  

Keep up with the latest NICER news by following NASA Universe on X and Facebook and check out the mission’s website. For more on space navigation, follow @NASASCaN on X or visit NASA’s Space Communications and Navigation website.  

Make sure to follow us on Tumblr for your regular dose of space!

“What in the world is that?” That’s a natural reaction when you first see this Hubble Space Telescope image of LL Pegasi. The extremely dim spiral pattern is real, and its regularity suggests a periodic origin for the nebula’s shape.

The spiral is thought to arise because LL Pegasi is a binary system, with a star that is losing material and a companion star orbiting it. The companion’s gravitational influence helps sculpt the nebula. The spacing between layers in the spiral reflects the 800-year orbital period of the binary.

Credit: ESA/NASA & R. Sahai.

ALT TEXT: At center left, a faint spiral structure with wide bands has a dark, dusty center. To its right, a bright white star displays four prominent diffraction spikes. A handful of smaller, more distant background galaxies are also scatted throughout the image.

I'm sure the visitors will arrive soon

The Bearclaw Nebula, Sh2-200 // Dionysus

2023 October 23

Moon Io from Spacecraft Juno Image Credit: NASA, JPL-Caltech, SwRI, MSSS; Processing & Copyright: Ted Stryk & Fernando García Navarro

Explanation: There goes another one! Volcanoes on Jupiter’s moon Io keep erupting. To investigate, NASA’s robotic Juno spacecraft has begun a series of visits to this very strange moon. Io is about the size of Earth’s moon, but because of gravitational flexing by Jupiter and other moons, Io’s interior gets heated and its surface has become covered with volcanoes. The featured image is from last week’s flyby, passing within 12,000 kilometers above the dangerously active world. The surface of Io is covered with sulfur and frozen sulfur dioxide, making it appear yellow, orange and brown. As hoped, Juno flew by just as a volcano was erupting – with its faint plume visible near the top of the featured image. Studying Io’s volcanoes and plumes helps humanity better understand how Jupiter’s complex system of moons, rings, and auroras interact. Juno is scheduled to make two flybys of Io during the coming months that are almost 10 times closer: one in December and another in February 2024.

∞ Source: apod.nasa.gov/apod/ap231023.html

Happy Monday!

Today's picture of the day was taken by Matthew Dominick from the ISS! The image shows a giant jet lightning, which is a new discovery (only 23 years!) and associated with thunderstorms. While regular lightning travels between the ground and the clouds, giant jet lightning bursts upwards.

We'll be open April 8th for the eclipse, too, with solar filters and projections of the Sun. Find us at Bridgewater State University's Science and Mathematics Center.

This animation portrays the creation of the cat’s tail in the southwest portion of Beta Pic’s secondary debris disk, estimated to span 10 billion miles. Read today's #AAS243 release to learn more: http://webbtelescope.pub/3RXt9Nx