SpaceX Starlink sat streaks now present in nearly a fifth of all astronomical images snapped by Caltech telescope

Annoying, maybe – but totally ruining this science, maybe not


SpaceX’s Starlink satellites appear in about a fifth of all images snapped by the Zwicky Transient Facility (ZTF), a camera attached to the Samuel Oschin Telescope in California, which is used by astronomers to study supernovae, gamma ray bursts, asteroids, and suchlike.

A study led by Przemek Mróz, a former postdoctoral scholar at the California Institute of Technology (Caltech) and now a researcher at the University of Warsaw in Poland, analysed the current and future effects of Starlink satellites on the ZTF. The telescope and camera are housed at the Palomar Observatory, which is operated by Caltech.

The team of astronomers found 5,301 streaks leftover from the moving satellites in images taken by the instrument between November 2019 and September 2021, according to their paper on the subject, published in the Astrophysical Journal Letters this week.

“In 2019, 0.5 per cent of twilight images were affected, and now almost 20 percent are affected," Mróz said.

The streaks appear as ugly bright marks in astronomers’ views of the night sky. They’re mostly visible during dusk and dawn, when they reflect the most light from the Sun. When it's nighttime, they’re mostly hidden from the ZTF. There are about 1,800 Starlink satellites orbiting our planet at this time.

Up to 15 satellites can crop up in each of its images if the astronomers are unlucky. On average, there are about 1.09 satellite streaks per affected image, the paper stated. The researchers also found that Starlink satellites sporting a visor to deflect sunlight appear about five times fainter compared to the standard design. They estimate that if SpaceX meets its target of growing its fleet of broadband satellites to 10,000 by 2027, all images captured by the ZTF will contain a Starlink streak. SpaceX has a long-term goal of 42,000 orbiting birds.

Operations at the ZTF aren’t derailed much by Starlink devices at the moment, however. In fact, the team reckon they shouldn’t be too much of a nuisance in the near future either.

“Having a streak in an image does not necessarily mean it is destroyed,” Mróz told The Register on Wednesday. A single streak only blocks out about less than one-tenth of a percent of the pixels in a ZTF image. It’s rare that these annoying bright flecks directly cover up an object astronomers are trying to study.

Having a streak in an image does not necessarily mean it is destroyed

"There is a small chance that we would miss an asteroid or another event hidden behind a satellite streak, but compared to the impact of weather, such as a cloudy sky, these are rather small effects for ZTF," said Tom Prince, an emeritus professor of physics at Caltech.

“Although the number of satellite streaks is rising,” Mróz added, "we have not come across any case in which a satellite streak would impact the discovery or monitoring of an asteroid."

The satellite streaks may not be so disruptive for astronomers using the ZTF since they study moving objects and phenomena. They can snap more images, and observe, say, asteroids moving out of the way of the satellites’ lines. Although the impact on the ZTF is minimal, that’s not the case for all observatories. The effect may be concerning for the upcoming Vera C. Rubin Observatory, under construction in Chile, which has a wider view of space.

“Different satellite constellations may impact astronomical observations differently,” Mróz told us. "In the paper, we demonstrated that even if SpaceX deploys the full constellation of 42,000 satellites, they won’t significantly impact science operations of ZTF, including studying asteroids, because less than one per cent of our pixels would be masked. However, this may not be true for other observatories."

It’s difficult to model the effect these devices will have on astronomy. And there are companies other than SpaceX planning to launch thousands of satellites that will occupy orbits around Earth.

The research community is trying to develop new techniques and strategies to prevent the birds from potentially destroying science. Many have suggested building open-source tools based on machine-learning algorithms to automatically detect and remove bright pixels leftover from streaks in images. Others are racing to update international space policies to force countries to regulate commercial satellite companies. ®


Other stories you might like

  • New York City rips out last city-owned public payphones
    Y'know, those large cellphones fixed in place that you share with everyone and have to put coins in. Y'know, those metal disks representing...

    New York City this week ripped out its last municipally-owned payphones from Times Square to make room for Wi-Fi kiosks from city infrastructure project LinkNYC.

    "NYC's last free-standing payphones were removed today; they'll be replaced with a Link, boosting accessibility and connectivity across the city," LinkNYC said via Twitter.

    Manhattan Borough President Mark Levine said, "Truly the end of an era but also, hopefully, the start of a new one with more equity in technology access!"

    Continue reading
  • Cheers ransomware hits VMware ESXi systems
    Now we can say extortionware has jumped the shark

    Another ransomware strain is targeting VMware ESXi servers, which have been the focus of extortionists and other miscreants in recent months.

    ESXi, a bare-metal hypervisor used by a broad range of organizations throughout the world, has become the target of such ransomware families as LockBit, Hive, and RansomEXX. The ubiquitous use of the technology, and the size of some companies that use it has made it an efficient way for crooks to infect large numbers of virtualized systems and connected devices and equipment, according to researchers with Trend Micro.

    "ESXi is widely used in enterprise settings for server virtualization," Trend Micro noted in a write-up this week. "It is therefore a popular target for ransomware attacks … Compromising ESXi servers has been a scheme used by some notorious cybercriminal groups because it is a means to swiftly spread the ransomware to many devices."

    Continue reading
  • Twitter founder Dorsey beats hasty retweet from the board
    We'll see you around the Block

    Twitter has officially entered the post-Dorsey age: its founder and two-time CEO's board term expired Wednesday, marking the first time the social media company hasn't had him around in some capacity.

    Jack Dorsey announced his resignation as Twitter chief exec in November 2021, and passed the baton to Parag Agrawal while remaining on the board. Now that board term has ended, and Dorsey has stepped down as expected. Agrawal has taken Dorsey's board seat; Salesforce co-CEO Bret Taylor has assumed the role of Twitter's board chair. 

    In his resignation announcement, Dorsey – who co-founded and is CEO of Block (formerly Square) – said having founders leading the companies they created can be severely limiting for an organization and can serve as a single point of failure. "I believe it's critical a company can stand on its own, free of its founder's influence or direction," Dorsey said. He didn't respond to a request for further comment today. 

    Continue reading
  • Snowflake stock drops as some top customers cut usage
    You might say its valuation is melting away

    IPO darling Snowflake's share price took a beating in an already bearish market for tech stocks after filing weaker than expected financial guidance amid a slowdown in orders from some of its largest customers.

    For its first quarter of fiscal 2023, ended April 30, Snowflake's revenue grew 85 percent year-on-year to $422.4 million. The company made an operating loss of $188.8 million, albeit down from $205.6 million a year ago.

    Although surpassing revenue expectations, the cloud-based data warehousing business saw its valuation tumble 16 percent in extended trading on Wednesday. Its stock price dived from $133 apiece to $117 in after-hours trading, and today is cruising back at $127. That stumble arrived amid a general tech stock sell-off some observers said was overdue.

    Continue reading
  • Amazon investors nuke proposed ethics overhaul and say yes to $212m CEO pay
    Workplace safety, labor organizing, sustainability and, um, wage 'fairness' all struck down in vote

    Amazon CEO Andy Jassy's first shareholder meeting was a rousing success for Amazon leadership and Jassy's bank account. But for activist investors intent on making Amazon more open and transparent, it was nothing short of a disaster.

    While actual voting results haven't been released yet, Amazon general counsel David Zapolsky told Reuters that stock owners voted down fifteen shareholder resolutions addressing topics including workplace safety, labor organizing, sustainability, and pay fairness. Amazon's board recommended voting no on all of the proposals.

    Jassy and the board scored additional victories in the form of shareholder approval for board appointments, executive compensation and a 20-for-1 stock split. Jassy's executive compensation package, which is tied to Amazon stock price and mostly delivered as stock awards over a multi-year period, was $212 million in 2021. 

    Continue reading
  • Confirmed: Broadcom, VMware agree to $61b merger
    Unless anyone out there can make a better offer. Oh, Elon?

    Broadcom has confirmed it intends to acquire VMware in a deal that looks set to be worth $61 billion, if it goes ahead: the agreement provides for a “go-shop” provision under which the virtualization giant may solicit alternative offers.

    Rumors of the proposed merger emerged earlier this week, amid much speculation, but neither of the companies was prepared to comment on the deal before today, when it was disclosed that the boards of directors of both organizations have unanimously approved the agreement.

    Michael Dell and Silver Lake investors, which own just over half of the outstanding shares in VMware between both, have apparently signed support agreements to vote in favor of the transaction, so long as the VMware board continues to recommend the proposed transaction with chip designer Broadcom.

    Continue reading

Biting the hand that feeds IT © 1998–2022