Following a computer anomaly aboard Hubble, which took a month to fix, NASA has released a pair of new images to demonstrate the spacecraft’s return to full scientific operations. Hubble’s scientific operations restarted on July 17 at 1:18 pm EDT. Following its operational return, Hubble’s early targets included globular star clusters in other galaxies and aurorae on Jupiter, plus a closer look at some bizarre galaxies.
The two released images focus on peculiar galaxies and are part of a program led by Julianne Dalcanton of the University of Washington in Seattle. The program’s purpose is surveying ‘oddball galaxies scattered across the sky.’
‘ARP-MADORE2115-273 is a rarely observed example of a pair of interacting galaxies in the southern hemisphere.’ Credits: Science: NASA, ESA, STScI, Julianne Dalcanton (UW) Image processing: Alyssa Pagan (STScI)
The first image is of ARP-MADORE2115-273. It’s a ‘rare example of an interacting galaxy pair in the southern hemisphere.’ Hubble’s recent observation is the craft’s first high-resolution look at this system. The system is located 297 million light-years away. Given a lack of prior observation, astronomers believed that the system was a ‘collisional ring’ system resulting from the merger of two galaxies. Still, the new Hubble observations show that the ongoing interaction between the galaxies is ‘far more complex, leaving behind a rich network of stars and dusty gas.’
The second galaxy Hubble recently observed is ARP-MADORE0002-503. It’s a large spiral galaxy with unusual, extended spiral arms. The galaxy is 490 million light-years away, and its arms extend to a radius of 163,000 light-years. This means that this galaxy is three times more expansion than our galaxy. Beyond its peculiar size, the spiral galaxy also has three spiral arms, whereas more disk galaxies possess an even number of arms.
‘ARP-MADORE0002-503 is a large spiral galaxy with unusual, extended spiral arms. While most disk galaxies have an even number of spiral arms, this one has three.’ Credits: Science: NASA, ESA, STScI, Julianne Dalcanton (UW) Image processing: Alyssa Pagan (STScI)
‘I’ll confess to having had a few nervous moments during Hubble’s shutdown, but I also had faith in NASA’s amazing engineers and technicians. Everyone is incredibly grateful, and we’re excited to get back to science!’ said Dalcanton.
Returning to the original issue with Hubble, NASA writes, ‘Hubble’s payload computer, which controls and coordinates the observatory’s onboard science instruments, halted suddenly on June 13. When the main computer failed to receive a signal from the payload computer, it automatically placed Hubble’s science instruments into safe mode. That meant the telescope would no longer be doing science while mission specialists analyzed the situation.’
The Hubble team worked to investigate the issue with the observatory, which orbits 547km (about 340 mi) above Earth. Engineers at NASA’s Goddard Space Flight Center in Greenbelt, Maryland and remote engineers collaborated to identify and solve the issue. Due to Hubble’s age, NASA had to rely on knowledge from a wide range of staff. While Hubble was launched in 1990, its telescope was built in the 1980s, meaning that the team required the help of staff from Hubble’s extensive history, including Hubble alumni. Some team members had to dig through Hubble’s original paperwork, reading through nearly four-decade-old documents.
On July 15, the team found that the possible cause of the issue was the Power Control Unit. That day, the team planned to switch to the backup side of the Science Instrument and Command & Data Handling unit, which includes the backup Power Control Unit. At 11:30 pm EDT on July 15, the team determined the switch was successful. Scientific instruments were brought back online, and full scientific work resumed on July 17.
‘Hubble is in good hands. The Hubble team has once again shown its resiliency and prowess in addressing the inevitable anomalies that arise from operating the world’s most famous telescope in the harshness of space,’ said Kenneth Sembach, director of the Space Telescope Science Institute (STScI) in Baltimore, Maryland, which conducts Hubble science operations. ‘I am impressed by the team’s dedication and common purpose over the past month to return Hubble to service. Now that Hubble is once again providing unprecedented views of the universe, I fully expect it will continue to astound us with many more scientific discoveries ahead.’