Nancy Grace Roman Space Telescope precision flying means an extended life observing the Universe

Extra "gas in the tank" will possibly double the latest space telescope's lifespan from 10 to 22 years plus!

We chatted about the launch of the Nancy Grace Roman Space Telescope a couple of weeks ago.

It's still early days in the life of this telescope as it heads to the L2 Lagrange Point where it will observe the Universe with the same resolution as Hubble but with a 100 times wider field of view. However, things are looking good!

First of all, NASA announced this week that thanks to a precision launch and a spot-on mid-course orbit correct burn, the lifespan of the Roman Space has essentially doubled.

Why does having spare fuel help extend the of the Roman Space Telescope?

Throughout the life of Roman, the telescope will require a burn of its thrusters about every 28 days to maintain its position and orientation. An orbit at L2 is not entirely stable due to influences of the Moon’s gravity, solar-radiation pressure on the space telescope and even
slight variations in the combined gravitational pull of Earth and the Sun. These small correction burns are called "station keeping". Without them, Roman will drift away from L2 or lose its orientation. When this happens, it will no longer be able to operate and its mission will finish. 

Because of this, the amount of fuel remaining in the spacecraft when it reaches L2 in a few months will heavily influence just how long Roman will be able to image the Universe. 

The mission was originally planned to last 10 years. First of all, the spacecraft when loaded onto the SpaceX Falcon Heavy proved to lighter than first planned. A near-perfect launch placed Roman into a better than hoped-for initial position. 

Fuel efficiencies during the course correction burns have bumped this number up considerably as well. This first one on the 31st of August 2026 used only 18kg of fuel instead of the planned for 200kg and this alone extended the mission life by more than 4 years. A second, upcoming burn is expected to be just as efficient. 

“As a result of exquisite planning by our orbital dynamics team, brilliant execution by the operations team, and a precise launch from SpaceX, Roman has fuel for at least 22 years of potential science operations,” said Jamie Dunn, center director at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

In other good news,  as Roman heads out to L2, mission controllers have started the process of commissioning its optical system and the results so far have been very promising. 

The telescope has "opened its eyes" as the Roman team has activated the Wide Field Instrument or WFI. 

Astronomers had to wait a few days after launch to allow the camera to decontaminate, dry out and cool down to math the conditions found in space. 

“After years of effort to build and test the instrument on the ground, we now have confirmation that it is operational in space. This is a huge milestone for the team at Goddard, our industry teams at BAE Systems, Inc. and Teledyne, and our science centers,” said Josh Schlieder, the Wide Field Instrument scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “There is much to do, but we are on our way to groundbreaking science.”

There's still some calibration and focusing to be done as the camera detector array was stored away and secured for launch. I'm sure any amateur astronomer will recognize the fuzzy stars they see until they focus their own telescope.

This test image captures the very first photons of starlight to reach the Wide Field Instrument on NASA’s Nancy Grace Roman Space Telescope. Image via NASA’s Goddard Space Flight Center, Tyler Desjardins (STScI)

So far, very promising news for Roman and we're all waiting for the first science images from this new space telescope. 

Read more here.

The Moon gets a new crater

Doesn't happen very often, at least by human lifespans

I was chatting at BINTEL about one of our Moon maps a few weeks ago with a young astronomer who was still in primary school and who asked me a very interesting question: "Do they bring out new editions when there are new craters on the Moon?"

The Moon does get new craters from meteorites and comets. It's estimated that there's over 180 small craters formed on the Moon every year that are 9m or more in diameter. Spacecraft like the LRO (Lunar Reconnaissance Orbiter) provide regular images that allow astronomers to compare "before and after" views of the Lunar surface.

(The Earth also receives an even greater number of potential impacts due to its larger size and greater gravitational attraction, however almost all of these burn up in our atmosphere. Any meteor heading towards the Moon will impact its surface as it has no such protective layer.)

Larger impacts which result in craters of over 100m are much rarer events, with the likelihood of them occurring more than 120 years apart. 

NASA announced this week that an impact from a meteorite or a comet the size of a six storey building* that occurred somewhere between April 11th and May 22nd, 2024 resulted in a new crater that's some 224 metres wide.

The new crater was spotted when a scientist working on the LRO images, scanned a giant Moon map on his computer screen

“I just stopped, dropped everything, and started looking into what that spot was,” said Robert Wagner, an image-processing specialist from Intuitive Machines who works with data from the Lunar Reconnaissance Orbiter Camera (LROC) system.

The small circle highlights the fresh material flung out by the impact, not the crater itself. Image on the right taken. Each frame show an area of the Moon about 60km wide. Image via NASA Goddard/Intuitive Machines/Robert Wagner

Why can't we narrow this date down a little more? Was the actual impact observed?

No. The body that impacted the Moon to form this latest crater wasn't spotted as it headed towards the Moon and the event itself also wasn't captured either from telescopes on Earth or from spacecraft orbiting the Moon. 

Can I see this new crater with my telescope?

No. Even big amateur telescopes can only spot Lunar features down to about 1km and this crater is awkwardly placed on the eastern limb of the Moon for observation from Earth. 

A close-up of the new Crater McGetchin

Going back to the original question about how often we need to update Moon maps, we generally don't need to. New craters on the Moon that are 100m or more only occur every few human lifespans and even these are too small to be recorded on Moon maps. 

Read more about this event the at the NASA site here. 

Spring Equinox this week

Image via timeanddate.com

The Spring Equinox in Australia for this year happens on Wednesday, 23 September 2026 Sydney time.

This is when all parts of the Earth experience about the same length of night and day and when the Sun crosses over the celestial equator into the southern part of the sky. 

In many parts of the world, especially in the northern hemisphere it marks the start of autumn. However in Australia we mark spring as starting on the 1st of September. The date of the equinoxes move around by a day or two and this way records were kept consistent to help with farmers. 

Did Venus swallow its own moon?

That super bright "star" you can spot tonight in the western sky just after the Sun sets is Venus. It reaches its peak brightness for the evening in 2026 this week on the 22nd of September, shining at magnitude −4.78 or over 20 times brighter than Sirius. We've had a lot of folks asking us here at BINTEL "I've seen this really bright star in the early evening sky and wondered if it was a plane or helicopter but is doesn't seem to move!" Yes, it's Venus we tell them and its a wonderful sight at the moment. 

One of the things that stands out about the Earth compared to the other inner rocky planets is that we have a large natural satellite. In fact our Moon is the largest in comparison to Earth than all the other planets in the Solar System. You could almost call the Earth and Moon a binary planet system.

Given just how close the Earth and Venus are size wise, why Venus never scored its own moon has always puzzled astronomers. Now a team led by Stephen R. Kane from the University of California, Riverside, have spent time trying to recreate computationally the early history of Venus and whether it could have held onto a large moon. 

In some of these scenarios, Venus' gravity could have torn a moon apart and then sent the remains crashing into its surface. This would have changed the Venusian surface and altered its ability to hold onto water. It also would have been a major factor in the conditions we see at Venus today. 

“When I made this discovery, I was shocked,” Kane said. “I thought surely the broad range of scenarios I was exploring would lead to a variety of results. But it all went pretty much in the same direction.”

Venus. Image via: NASA/JPL/Caltech

This doesn't answer the question about whether Venus ever had a large moon. Rather it points towards if one was captured or formed through a collision like our own Moon was, there was a good chance it would have not been able to orbit Venus for billions of years. The findings also have implications for Earth-like exoplanets orbiting other stars.

“When people think about Earth twins around other stars, one question they ask is, ‘Does it have a moon?’” Kane said.

Read more about it here.

Mercury might have shrunk more than we originally thought

The closest planet to the Sun, Mercury is also in the news at the moment as new spacecraft prepares to start observing the planet.

We've also known for over 50 years that Mercury is shrinking. Flybys of the planet by the Mariner 10 spacecraft launched 1973 showed a series of enormous curved cliffs called, lobate scarps, some of which were sometimes hundreds of kilometres long and more than a kilometre high. These were signs of the outer crust no longer fitting around the cooling and shrinking metallic core. The amount of shrinking was not thought to be that much at first, maybe one or two km.

The MESSENGER spacecraft which orbited around Mercury from 2011 to 2015 found many more scarps and wrinkle ridges and these results were used to bump the shrinkage to about 7km. Think of these as wrinkles appearing on a piece of fruit as it dries out and shrinks. 

Researchers from Hokkaido University, in collaboration with the German Aerospace Center (DLR) and The University of Tokyo, have looked at these results and realised they were off by about 10–30% and Researchers now estimate that Mercury may have contracted by 10–30% more than previous calculations suggested. Its radius may have decreased by as much as 11.5 kilometres, equivalent to a reduction of about 23 kilometres across its diameter, since the planet formed.

This is because some of the later impacts and the debris thrown up, called ejecta, might have covered up some of the older scarps. Basically the Mariner 10 and MESSENGER spacecraft were not seeing just how much "wrinkling" there was on Mercury's surface.

Artist impression of the MESSENGER spacecraft in orbit at Mercury. Image via NASA

Is Mercury still shrinking today?

Yes, but the inner core has cooled significantly and the amount is likely small. Most of the contraction of the planet would have occurred much earlier in the Solar System's history.

What's next?

The BepiColombo spacecraft has almost arrived at Mercury and is about to begin its science mission. We'll hopefully learn more in the coming months and years.

Where to spot the Solar System's inner planets tonight

Both Mercury and Venus will be visible in the western evening sky as the Sun sets. There's no missing Venus as it will be the brightest "star" in the evening sky by a long way! Mercury will be trickier.

Mercury as seen tonight, 19th September 2026, from Sydney at about 6.20pm. It will be hard to spot being so low in the western sky just after sunset

When you head outside this weekend to look up at the three closest neighbours to us in the Solar System, it's worth remembering that astronomers are always finding ways to learn more about these ancient bodies. 

Cheers,

Earl White

BINTEL 19th September 2026

*Not sure how big that is compared to the other measure of astronomical units, "the corgi".