Astronomy Archives

October 10, 2023October 10, 2023 by Evan Gough

Seeing the Moment Planets Start to Form

ALMA captured this high-resolution image of the protoplanetary disk surrounding DG Taurus at a 1.3 mm wavelength. The young star is still embedded in its disk, and the smooth appearance, absent of ring-like structures, indicates a phase shortly before planets form. Credit: ALMA (ESO/NAOJ/NRAO), S. Ohashi, et al.

Nature makes few duplicates, and planets are as distinct from one another as snowflakes are. But planets all start out in the same circumstances: the whirling disks of material surrounding young stars. ALMA’s made great progress imaging these disks and the telltale gaps excavated by young, still-forming planets.

But new images from ALMA (Atacama Large Millimeter/submillimeter Array) show a star and disk so young that there are no telltale gaps in the disk. Is this the moment that planets start to form?

October 10, 2023October 10, 2023 by David Dickinson

Ring of Fire: Catching This Weekend’s ‘Great North American Annular Solar Eclipse’

Don’t miss the final solar eclipse of the year: a striking ‘ring of fire’ annular solar eclipse.

If skies are clear, observers across a swath of the western United States, Mexico, and Central and South America are in for a treat this coming Saturday, October 14th, as the antumbral shadow of the Moon crosses the Earth in a fine ‘ring of fire’ annular solar eclipse.

October 10, 2023October 10, 2023 by Scott Alan Johnston

Earth's Smallest Flowering Plant Can Handle 20X Earth's Gravity

Confocal Laser Scanning Microscope image of approximately 1mm-diameter watermeal plants after hypergravity exposure. ESA.

Astronauts need to eat, and they need to breathe. That means, for long-duration missions, they are going to need to bring plants with them. But not all plants are created equal, and not all can survive the harsh conditions of space. One that might thrive on long spacefaring voyages also happens to be the smallest flowering plant on Earth.

October 9, 2023October 9, 2023 by Matt Williams

Euclid Recovers From a Navigation Problem and Finds its Guide Stars Again

Artist impression of the Euclid mission in space. Credit: ESA

On July 1st, 2023, the ESA’s Euclid mission headed for space, where it began its mission to observe the Universe and measure its expansion over time. The commissioning process began well as the mission team spent weeks testing and calibrating the observatory, then flew the mission out to Lagrange Point 2 (LP2). The telescope focused its mirrors, collected its “first light,” and the first test images it took were breathtaking! Unfortunately, Euclid hit a snag when its Fine Guidance Sensor (FGS) failed to lock onto its “guide stars.”

According to the latest update from the ESA, Euclid has found its guide stars again, thanks to a software patch. With its navigation woes now solved and its observation schedule updated, the telescope will now undergo its Performance Verification phase (its final phase of testing) in full “science mode.” Once that’s complete, Euclid will commence its nominal six-year mission, providing razor-sharp images and deep spectra of our Universe, looking back 10 billion years. This data will be used to create a grand survey of one-third of the entire sky and measure the influence of Dark Matter and Dark Energy.

October 8, 2023October 8, 2023 by Scott Alan Johnston

M87's Jet is Triggering Novae

The jet emerging from the galactic core of M87. NASA/STScI/AURA.

Everyone loves a good mystery, and astronomers have just uncovered a new one in a nearby supermassive galaxy called M87. Like most galaxies, M87 regularly plays host to a smattering of stellar explosions called novae, each the result of a star stealing material from a neighbour. M87 also features a massive jet of plasma blasting out into deep space from the galactic core. These phenomena: the jet and the novae, are unrelated astronomical occurrences, or so scientists believed. But astronomers recently discovered that the novae in M87 seem to be uncharacteristically aligned along the jet, instead of scattered randomly throughout the galaxy. Is the jet somehow triggering nova explosions?

It might be, but the mystery is: how?

October 7, 2023October 7, 2023 by Matt Williams

Hubble Sees a Mysterious Flash in Between Galaxies

Artist’s concept of one of brightest explosions ever seen in space: a Luminous Fast Blue Optical Transient (LFBOT). Credit: NASA

While the night sky may appear tranquil (and incredibly beautiful), the cosmos is filled with constant stellar explosions and collisions. Among the rarest of these transient events are what is known as Luminous Fast Blue Optical (LFBOTs), which shine intensely bright in blue light and fade after a few days. These transient events are only detectable by telescopes that continually monitor the sky. Using the venerable Hubble Space Telescope, an international team of astronomers recently observed an LFBOT far between two galaxies, the last place they expected to see one.

October 6, 2023October 6, 2023 by Matt Williams

Colliding Neutron Stars Could Help Measure the Expansion of the Universe

Artist's impression of two neutron stars colliding, known as a "kilonova" event. Credits: Elizabeth Wheatley (STScI)

According to some in the astrophysical community, there has been something of a “Crisis in Cosmology” in recent years. Though astronomers are all aware that the Universe is in a state of expansion, there has been some inconsistency when measuring the rate of it (aka. the Hubble Constant). This issue arises from the Cosmic Distance Ladder, where astronomers use different methods to measure relative distances over longer scales. This includes making local distance estimates using parallax measurements, nearby variable stars, and supernovae (“standard candles”).

They also conduct redshift measurements of the Cosmic Microwave Background (CMB), the relic radiation left over from the Big Bang, to determine cosmological distances. The discrepancy between these two methods is known as the “Hubble Tension,” and astronomers are eager to resolve it. In a recent study, an international team of astrophysicists from the Niels Bohr Institute suggested a novel method for measuring cosmic expansion. They argue that by observing colliding neutron stars (kilonovae), astronomers can relieve the tension and obtain consistent measurements of the Hubble Constant.

October 6, 2023October 6, 2023 by Evan Gough

One of the Brightest Stars in the Sky is Actually a Satellite

The bright streaks drawing an arc across the night sky are caused by the satellite BlueWalker 3. The prototype satellite is brighter than most stars. Image Credit: Ilse Plauchu-Frayn

Back in the 70s, kids used to look up at the summer sky and try to be the first one to shout, “Satellite!” That seems like a relic from the past now, alongside Polaroid cameras and astronauts on the Moon. These days, it’s rare to spend any amount of time looking at the sky without seeing a satellite, or several of them.

A new satellite is emphasizing that fact. It’s a prototype communications satellite with a roughly 700-square-foot antenna, and it’s brighter than most stars.

October 5, 2023October 5, 2023 by Matt Williams

Those Impossibly Massive Early Galaxies Might Just Be Surprisingly Bright

Artist conception of starbursting galaxies in the early universe. Stars and galaxies are shown in the bright white points of light, while the more diffuse dark matter and gas are shown in purples and reds. Early gas clouds bounced past dark matter clumps, only to clump together again under dark matter's gravity -- sparking off star formation. Credit: Aaron M. Geller/Northwestern/CIERA + IT-RCDS

On July 12th, 2022, in an event live-streamed from the NASA Goddard Spaceflight Center, the James Webb Space Telescope’s (JWST) first images were released! Among them was the most detailed image of SMACS 0723, showing galaxy clusters and the gravitational lenses they produced. These lenses allowed astronomers to see deeper into the cosmos and spot galaxies as they appeared less than one billion years after the Big Bang (ca. 13 billion years ago). Upon further examination, however, they noticed something rather surprising about these early galaxies: they were much larger than expected!

According to the standard model of cosmology, the earliest galaxies in the Universe did not have enough time to become as bright, massive, and mature as they appeared. This raised many questions about our cosmological models and whether or not the Universe was older than previously thought. According to new simulations by a Northwestern University-led team of astrophysicists, these galaxies may not be so massive after all. According to their findings, they appear larger due to irregular and very bright bursts of star formation.

October 5, 2023October 5, 2023 by Scott Alan Johnston

Can JWST Tell the Difference Between an Exo-Earth and an Exo-Venus?

Earth and Venus. Why are they so different and what do the differences tell us about rocky exoplanet habitability? Image Credit: NASA

As of this month, astronomers have discovered 5,506 exoplanets orbiting other stars. That number is growing daily, and astronomers are hoping, among other things, to find Earth-like worlds. But will we know one when we see it? How might we be able to tell an Earth-like garden from a Venus-like pressure cooker from upwards of 40 light years away? Is JWST up to the challenge?