One thing we’ve learned in recent decades is that exoplanets are surprisingly common. So far, we’ve confirmed nearly 6,000 planets, and we have evidence for thousands more. Most of these planets were discovered using the transit method. though we there are other methods as well. Many stars are known to have multiple planets, such as the TRAPPIST-1 system with seven Earth-sized worlds. But even within known planetary systems there could be planets we’ve overlooked. Perhaps their orbit doesn’t pass in front of the star from our vantage point, or the evidence of their presence is buried in data noise. How might we find them? A recent paper on the arXiv has an interesting approach.
Continue reading “How Many Additional Exoplanets are in Known Systems?”Hubble and Webb are the Dream Team. Don't Break Them Up
Many people think of the James Webb Space Telescope as a sort of Hubble 2. They understand that the Hubble Space Telescope (HST) has served us well but is now old, and overdue for replacement. NASA seems to agree, as they have not sent a maintenance mission in over fifteen years, and are already preparing to wind down operations. But a recent paper argues that this is a mistake. Despite its age, HST still performs extremely well and continues to produce an avalanche of valuable scientific results. And given that JWST was never designed as a replacement for HST — it is an infrared (IR) telescope) — we would best be served by operating both telescopes in tandem, to maximize coverage of all observations.
Continue reading “Hubble and Webb are the Dream Team. Don't Break Them Up”Scientists Have Figured out why Martian Soil is so Crusty
On November 26th, 2018, NASA’s Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport (InSight) mission landed on Mars. This was a major milestone in Mars exploration since it was the first time a research station had been deployed to the surface to probe the planet’s interior. One of the most important instruments InSight would use to do this was the Heat Flow and Physical Properties Package (HP3) developed by the German Aerospace Center (DLR). Also known as the Martian Mole, this instrument measured the heat flow from deep inside the planet for four years.
The HP3 was designed to dig up to five meters (~16.5 ft) into the surface to sense heat deeper in Mars’ interior. Unfortunately, the Mole struggled to burrow itself and eventually got just beneath the surface, which was a surprise to scientists. Nevertheless, the Mole gathered considerable data on the daily and seasonal fluctuations below the surface. Analysis of this data by a team from the German Aerospace Center (DLR) has yielded new insight into why Martian soil is so “crusty.” According to their findings, temperatures in the top 40 cm (~16 inches) of the Martian surface lead to the formation of salt films that harden the soil.
Continue reading “Scientists Have Figured out why Martian Soil is so Crusty”Another Way to Extract Energy From Black Holes?
The gravitational field of a rotating black hole is powerful and strange. It is so powerful that it warps space and time back upon itself, and it is so strange that even simple concepts such as motion and rotation are turned on their heads. Understanding how these concepts play out is challenging, but they help astronomers understand how black holes generate such tremendous energy. Take, for example, the concept of frame dragging.
Continue reading “Another Way to Extract Energy From Black Holes?”Plastic Waste on our Beaches Now Visible from Space, Says New Study
According to the United Nations, the world produces about 430 million metric tons (267 U.S. tons) of plastic annually, two-thirds of which are only used for a short time and quickly become garbage. What’s more, plastics are the most harmful and persistent fraction of marine litter, accounting for at least 85% of total marine waste. This problem is easily recognizable due to the Great Pacific Garbage Patch and the amount of plastic waste that washes up on beaches and shores every year. Unless measures are taken to address this problem, the annual flow of plastic into the ocean could triple by 2040.
One way to address this problem is to improve the global tracking of plastic waste using Earth observation satellites. In a recent study, a team of Australian researchers developed a new method for spotting plastic rubbish on our beaches, which they successfully field-tested on a remote stretch of coastline. This satellite imagery tool distinguishes between sand, water, and plastics based on how they reflect light differently. It can detect plastics on shorelines from an altitude of more than 600 km (~375 mi) – higher than the International Space Station‘s (ISS) orbit.
Continue reading “Plastic Waste on our Beaches Now Visible from Space, Says New Study”Future Space Telescopes Could be Made From Thin Membranes, Unrolled in Space to Enormous Size
Space-based telescopes are remarkable. Their view isn’t obscured by the weather in our atmosphere, and so they can capture incredibly detailed images of the heavens. Unfortunately, they are quite limited in mirror size. As amazing as the James Webb Space Telescope is, its primary mirror is only 6.5 meters in diameter. Even then, the mirror had to have foldable components to fit into the launch rocket. In contrast, the Extremely Large Telescope currently under construction in northern Chile will have a mirror more than 39 meters across. If only we could launch such a large mirror into space! A new study looks at how that might be done.
Continue reading “Future Space Telescopes Could be Made From Thin Membranes, Unrolled in Space to Enormous Size”Voyager 1 is Forced to Rely on its Low Power Radio
Voyager 1 was launched waaaaaay back in 1977. I would have been 4 years old then! It’s an incredible achievement that technology that was built THAT long ago is still working. Yet here we are in 2024, Voyager 1 and 2 are getting older. Earlier this week, NASA had to turn off one of the radio transmitters on Voyager 1. This forced communication to rely upon the low-power radio. Alas technology around 50 years old does sometimes glitch and this was the result of a command to turn on a heater. The result was that Voyager 1 tripped into fault protection mode and switch communications! Oops.
Continue reading “Voyager 1 is Forced to Rely on its Low Power Radio”Webb Confirms a Longstanding Galaxy Model
Perhaps the greatest tool astronomers have is the ability to look backward in time. Since starlight takes time to reach us, astronomers can observe the history of the cosmos by capturing the light of distant galaxies. This is why observatories such as the James Webb Space Telescope (JWST) are so useful. With it, we can study in detail how galaxies formed and evolved. We are now at the point where our observations allow us to confirm long-standing galactic models, as a recent study shows.
Continue reading “Webb Confirms a Longstanding Galaxy Model”The Aftermath of a Neutron Star Collision Resembles the Conditions in the Early Universe
Neutron stars are extraordinarily dense objects, the densest in the Universe. They pack a lot of matter into a small space and can squeeze several solar masses into a radius of 20 km. When two neutron stars collide, they release an enormous amount of energy as a kilonova.
That energy tears atoms apart into a plasma of detached electrons and atomic nuclei, reminiscent of the early Universe after the Big Bang.
Continue reading “The Aftermath of a Neutron Star Collision Resembles the Conditions in the Early Universe”New View of Venus Reveals Previously Hidden Impact Craters
Think of the Moon and most people will imagine a barren world pockmarked with craters. The same is likely true of Mars albeit more red in colour than grey! The Earth too has had its fair share of craters, some of them large but most of the evidence has been eroded by centuries of weathering. Surprisingly perhaps, Venus, the second planet from the Sun does not have the same weathering processes as we have on Earth yet there are signs of impact craters, but no large impact basins! A team of astronomers now think they have secured a new view on the hottest planet in the Solar System and revealed the missing impact sites.
Continue reading “New View of Venus Reveals Previously Hidden Impact Craters”