There have been numerous robotic space missions reach the end of their operating life over the years and for a multitude of reasons. Be they catastrophic failure or a scheduled end but I must say one that has recently made me a little sad is the demise of the Ingenuity helicopter on Mars. It sustained damage after its recent flight and can now no longer fly. In a mission that was supposed to complete five flights in 30 days, the plucky little helicopter completed 72 flights over three years!
What were you doing last Saturday? As it turns out, I was doing something rather unexciting… Trying to fix my washing machine (I did – in case you are interested). At the same time, Hungarian geography teacher by day and asteroid hunter by night Krisztián Sárneczky was out observing and detected a small asteroid which it transpired was on a collision course with Earth!
It’s been a big week for Chinese space exploration. First a successful test flight of Zhuque-3 and this week we learned of their plans to explore the Moon’s South Pole. Previous missions have even returned samples to Earth but the Chinese landers have yet to explore more southerly areas of the Moon. Chang’e-6 is due to launch in a few months to collect samples from the far side of the Moon while Chang’e-7 launches in 2026 to the Moon’s south pole.
The sight of a Falcon-9 rocket landing in an upright orientation is not an unusual sight. It seems that the Chinese aerospace firm LandSpace is getting in on the act with their new Zhuque-3 (I don’t even know how to pronounce that) reusable methane rocket. The prototype booster took off, reached a height of 350 metres and landed 60 seconds later about 100 metres away on a landing pad. LandSpace have revealed this test showcases key technologies that will be used for their upcoming reusable rocket.
It seems crazy that Uranus was discovered in 1781 yet here we are, in 2024 and we have only sent one spacecraft to explore Uranus. Voyager 2 is the only spacecraft to have given us close-up images of Uranus (and Neptune) but since their visit in 1986, we have not returned. There have of course been great images from the Hubble Space Telescope and from the James Webb Space Telescope but we still have lots to learn about them.
Axiom Mission 3 (Ax-3), the third all private astronaut mission to the International Space Station, lifted off at 4:49pm EST on Thursday Jan 18 from Launch Complex 39A at NASA’s Kennedy Space Center in Florida. NASA
A few decades ago, the idea of private individuals travelling to the International Space Station was as much science fiction as a time travelling police box. Yet here we are, in 2024 and a crew of four private astronauts are on board the ISS. The team will spend about two weeks undertaking various experiments, commercial activities and outreach tasks.
The moment of separation between Superheavy and Starship. Credit: SpaceX
SpaceX is often in the headlines, unfortunlatey its not always good news. On 18th November we saw the second of the Starship and SuperHeavy booster get off the launchpad successfully, it failed before reaching orbit. In a recent event, Elon Musk explained how a fuel venting near the end of the burn was responbie but entirely avoidable next time!
Though an estimated 100 million black holes roam among the stars in our Milky Way galaxy, astronomers have never identified an isolated black hole – until now. Following six years of meticulous observations, NASA’s Hubble Space Telescope has provided, for the first time ever, strong evidence for a lone black hole plying interstellar space.
The black hole that was detected lies about 5,000 light-years away, in the Carina-Sagittarius spiral arm of our galaxy. However, its discovery allows astronomers to estimate, statistically, that the nearest isolated black hole to Earth might be as close as 80 light-years.
Black holes are born from rare, monstrous stars (less than one-thousandth of the galaxy’s stellar population) that are at least 20 times more massive than our Sun. These stars explode as supernovae, and the remnant core is crushed by gravity into a black hole. Because the self-detonation is not perfectly symmetrical, the black hole may get a kick, and go careening through our galaxy like a blasted cannonball.
Hubble can’t photograph the wayward black hole because it doesn’t emit any light, but instead swallows all radiation due to its intense gravitational pull. Instead, Hubble measurements capture the ghostly gravitational footprint of how the stealthy black hole warps space, which then deflects starlight from anything that momentarily lines up exactly behind it.
Ground-based telescopes, which monitor the brightness of millions of stars in the rich star fields in the direction of the central bulge of our Milky Way, look for the tell-tale sudden brightening of one of them when a massive object passes between us and the star. Then Hubble follows up on the most interesting such events.
Kailash Sahu of the Space Telescope Science Institute in Baltimore, Maryland, along with his team, made the discovery in a survey designed to find just such isolated black holes. The warping of space due to the gravity of a foreground object passing in front of a star located far behind it will momentarily bend and amplify the light of the background star as it passes in front of it. The phenomenon, called gravitational microlensing, is used to study stars and exoplanets in the approximately 20,000 events seen so far inside our galaxy.
The signature of a foreground black hole stands out as unique among other microlensing events. The very intense gravity of the black hole will stretch out the duration of the lensing event for over 200 days. Also, If the intervening object was instead a foreground star, it would cause a transient color change in the starlight as measured because the light from the foreground and background stars would momentarily be blended together. But no color change was seen in the black hole event.
Next, Hubble was used to measure the amount of deflection of the background star’s image by the black hole. Hubble is capable of the extraordinary precision needed for such measurements. The star’s image was offset from where it normally would be by two milliarcseconds. That’s equivalent to measuring the diameter of a 25-cent coin in Los Angeles as seen from New York City.
This astrometric microlensing technique provided information on the mass, distance, and velocity of the black hole. The amount of deflection by the black hole’s intense warping of space allowed Sahu’s team to estimate it weighs seven solar masses.
The isolated black hole is traveling across the galaxy at 90,000 miles per hour (fast enough to travel from Earth to the moon in less than three hours). That’s faster than most of the other neighboring stars in that region of our galaxy.
“Astrometric microlensing in conceptually simple but observationally very tough,” said Sahu. “It is the only technique for identifying isolated black holes.” When the black hole passed in front of a background star located 28,000 light-years away in the galactic bulge, the starlight coming toward Earth was amplified for a duration of 265 days as the black hole passed by. However, it took several years of Hubble observations to follow how the background star’s position appeared to be deflected by the bending of light by the foreground black hole.
The existence of stellar-mass black holes has been known since the early 1970’s, but all of them—until now—are found in binary star systems. Gas from the companion star falls into the black hole, and is heated to such high temperatures that it emits X rays. About two dozen black holes have had their masses measured in X-ray binaries through their gravitational effect on their companions.
Black hole masses in X-ray binaries inside our galaxy range from 5 to 20 solar masses. Black holes detected in other galaxies by gravitational waves from mergers between black holes and companion objects have been as high as 90 solar masses.
“Detections of isolated black holes will provide new insights into the population of these objects in our Milky Way,” said Sahu. He expects that his program will uncover more free-roaming black holes inside our galaxy. But it is a needle-in-a-haystack search. The prediction is that only one in 1500 microlensing events are caused by isolated black holes.
NASA’s upcoming Nancy Grace Roman Space Telescope will discover several thousand microlensing events out of which many are expected to be black holes, and the deflections will be measured with very high accuracy.
In a 1916 paper on general relativity, Albert Einstein predicted that his theory could be tested by observing the sun’s gravity offsetting the apparent position of a background star. This was tested by astronomer Arthur Eddington during a solar eclipse on May 29, 1919. Eddington measured a background star being offset by 2 arc seconds, validating Einstein’s theories. Both scientists could hardly have imagined that over a century later this same technique would be used – with unimaginable precision of a thousandfold better — to look for black holes across the galaxy.
Talk to anyone about galaxies and it often conjurs up images of spiral or elliptical galaxie. Thanks to a survey by the James Webb Space Telescope it seems the early Universe was full of galaxies of different shapes. In the first 6 billion years up to 80% of the galaxies were flat, surfboard like. But that’s not it, there were others like pool noodles too, yet why they looked so different back then is a mystery.
Solar power is a booming industry right now as we all strive to run our lives with minimum carbon footprint. Solar is a relatively easy way to get clean electricity but of course we are limited to the hours then Sun is above the horizon. Solar panels in space have been muted before but the costs and technology to transmit power to Earth is prohibitive. An alternative approach has been explored by a team of engineers who have been looking at the possibility of deploying giant reflectors into space.
OSIRIS REx curation team attempting to remove the two stuck fasteners that are currently prohibiting the complete opening of the TAGSAM head. Photo Date: January 10, 2024. Location: Bldg. 31 - 2nd Floor - OSIRIS-REx lab. Photographer: Robert Markowitz
We have all been there, had that one stubborn jar of jam that we just can’t open. Maybe you grab a rubber band or run it under warm water and its an easy fix but just imagine when the jar is a module from a $1.16 billion interplanetary probe! That’s what happened to NASA engineers when they were trying to recover samples from the OSIRIS-REx module when they discovered the clamps had cold welded shut!
