The Nancy Grace Roman Space Telescope, set to launch in 2027, is expected to revolutionize our understanding of the universe with its advanced capabilities and expansive survey scope. One of the telescope’s major surveys, the High-Latitude Time-Domain Survey, will scan a large region of space every five days for two years, stitching together observations to create movies that uncover all sorts of cosmic fireworks.

Cosmic explosions offer clues to some of the biggest mysteries of the universe, including the nature of dark energy. Scientists predict Roman will see around 100,000 celestial blasts, ranging from exploding stars to feeding black holes. This includes:

* Exploding stars: The survey is geared toward finding type Ia supernovae, which allow scientists to measure cosmic distances and trace the universe’s expansion.
* Feeding black holes: Roman will push the boundaries of how far back in time we can see these events, including more than a thousand that exploded more than 10 billion years ago.
* Tidal disruption events: Scientists think Roman’s survey will unveil 40 tidal disruption events, offering a chance to learn more about black hole physics.

While searching for type Ia supernovae, Roman is going to collect a lot of cosmic “bycatch” – other phenomena that aren’t useful to some scientists, but will be invaluable to others. The team estimates Roman will also spot:

* Core-collapse supernovae: About 60,000 of these events, which occur when a massive star runs out of fuel and collapses under its own weight.
* Superluminous supernovae: More than 90 of these blasts, which can be 100 times brighter than a typical supernova.
* Kilonovae: Several of these rare events, which occur when two neutron stars collide.

Roman may even spot the detonations of some of the first stars that formed in the universe. These nuclear furnaces were giants, up to hundreds of times more massive than our Sun, and unsullied by heavy elements that hadn’t yet formed. Scientists think Roman will make the first confirmed detection of a pair-instability supernova.

The Roman Space Telescope is set to uncover secrets of the universe with its advanced capabilities and expansive survey scope. With its ability to scan large regions of space every five days for two years, it’s expected to revolutionize our understanding of cosmic explosions and their role in shaping the universe.

The Cosmic Conundrum: A Billion-Light-Year Hole Around Earth Unmasks Faster Space Expansion

Astronomers have long been puzzled by the discrepancy in the measured expansion rate of the universe, which they refer to as the Hubble tension. This conundrum has left scientists searching for a solution, and recent research suggests that our galaxy might be situated within a massive, billion-light-year hole that makes the cosmos expand faster here than in neighboring regions.

The idea is not new, but it gained momentum with the latest study presented at the Royal Astronomical Society’s National Astronomy Meeting (NAM) in Durham. The researchers’ theory proposes that our galaxy sits near the center of a large, local void, which would cause matter to be pulled by gravity towards the higher-density exterior of the void.

As the void empties out over time, the velocity of objects away from us would increase, giving the appearance of a faster local expansion rate. This potential solution to the Hubble tension is largely a local phenomenon, with little evidence that the expansion rate disagrees with expectations in the standard cosmology further back in time.

The researchers also used baryon acoustic oscillations (BAOs) – essentially the sound waves from the early universe – to support their theory. These sound waves travelled for only a short while before becoming frozen in place once the universe cooled enough for neutral atoms to form. They act as a standard ruler, whose angular size can be used to chart the cosmic expansion history.

By considering all available BAO measurements over the last 20 years, the researchers showed that a void model is about one hundred million times more likely than a void-free model with parameters designed to fit the CMB observations taken by the Planck satellite, the so-called homogeneous Planck cosmology.

The next step for researchers is to compare their local void model with other methods to estimate the history of the universe’s expansion. This involves looking at galaxies that are no longer forming stars and observing their spectra or light to find what kinds of stars they have and in what proportion.

Astronomers can then combine this age with the galaxy’s redshift – how much the wavelength of its light has been stretched – which tells us how much the universe has expanded while light from the galaxy was traveling towards us. This sheds light on the universe’s expansion history.

The Hubble constant was first proposed by Edwin Hubble in 1929 to express the rate of the universe’s expansion. It can be measured by observing the distance of celestial objects and how fast they are moving away from us. The Hubble tension refers to the discrepancy in the measured expansion rate of the universe, specifically between the value based on observations of the early universe and the value related to observations of the local universe.

Baryon acoustic oscillations provide an independent way to measure the expansion rate of the universe and how that rate has changed throughout cosmic history. The discovery of a billion-light-year hole around Earth might be just the solution scientists need to unravel the mysteries of the cosmos.

NASA’s Parker Solar Probe has captured stunning new images from within the Sun’s atmosphere, revealing the origins of solar storms that can affect Earth. The probe, which flew closer to the Sun than ever before, has helped scientists better understand the Sun’s influence across the solar system.

The newly released images show the corona and solar wind, a constant stream of electrically charged particles from the Sun that rage across the solar system. The solar wind expands throughout the solar system with wide-ranging effects, including generating auroras, stripping planetary atmospheres, and inducing electric currents that can overwhelm power grids and affect communications at Earth.

Understanding the impact of solar wind starts with understanding its origins at the Sun. The WISPR images give scientists a closer look at what happens to the solar wind shortly after it is released from the corona. The images show the important boundary where the Sun’s magnetic field direction switches from northward to southward, called the heliospheric current sheet.

The collision of multiple coronal mass ejections (CMEs), or large outbursts of charged particles, has been captured for the first time in high resolution. “In these images, we’re seeing the CMEs basically piling up on top of one another,” said Angelos Vourlidas, the WISPR instrument scientist at the Johns Hopkins Applied Physics Laboratory.

When CMEs collide, their trajectory can change, making it harder to predict where they’ll end up. Their merger can also accelerate charged particles and mix magnetic fields, which makes the CMEs’ effects potentially more dangerous to astronauts and satellites in space and technology on the ground.

The solar wind was first theorized by preeminent heliophysicist Eugene Parker in 1958. His theories about the solar wind, which were met with criticism at the time, have now been confirmed through Parker Solar Probe’s close-up views of the Sun.

As it spiraled closer to the Sun, Parker Solar Probe helped scientists pinpoint the origin of switchbacks at patches on the visible surface of the Sun where magnetic funnels form. The fast solar wind, which travels at just 220 miles per second, has been shown to be in part powered by these switchbacks, adding to a 50-year-old mystery.

The slow solar wind, which is twice as dense and more variable than fast solar wind, is important to study because its interplay with the fast solar wind can create moderately strong solar storm conditions at Earth sometimes rivaling those from CMEs. Prior to Parker Solar Probe, distant observations suggested there are actually two varieties of slow solar wind, distinguished by the orientation or variability of their magnetic fields.

One type of slow solar wind, called Alfvénic, has small-scale switchbacks. The second type, called non-Alfvénic, doesn’t show these variations in its magnetic field. As it spiraled closer to the Sun, Parker Solar Probe confirmed there are indeed two types.

Its close-up views are also helping scientists differentiate the origins of the two types, which scientists believe are unique. The non-Alfvénic wind may come off features called helmet streamers — large loops connecting active regions where some particles can heat up enough to escape — whereas Alfvénic wind might originate near coronal holes, or dark, cool regions in the corona.

In its current orbit, bringing the spacecraft just 3.8 million miles from the Sun, Parker Solar Probe will continue to gather additional data during its upcoming passes through the corona to help scientists confirm the slow solar wind’s origins. The next pass comes Sept. 15, 2025.