A well-known astronomer and satellite tracker has voiced concerns that efforts to scan the skies for potentially dangerous near-Earth asteroids might be in jeopardy due to ambitious plans by SpaceX to deploy over 12,000 satellites in low-Earth orbit over the next several years.
The study “The Low Earth Orbit Satellite Population and Impacts of the SpaceX Starlink” by Jonathan McDowell from the Harvard-Smithsonian Centre for Astrophysics analyses the impact that the broadband service mega-constellation could have on different observatories.
Delighted to announce that my Starlink paper has been accepted for publication in Astrophysical Journal Letters and will be on the arxiv on Wed; and you can download the preprint version now at https://t.co/s4sQtLozGE— Jonathan McDowell (@planet4589) March 16, 2020
The research, still awaiting peer review and accepted for pre-print publication in Astrophysical Journal Letters, states:
"Astronomers - and casual viewers of the night sky - must expect a future in which the low Earth orbit population includes tens of thousands of relatively large satellites."
The researcher has modelled how many satellites in a constellation of 12,000 that the FCC has already approved for SpaceX would be lit up by the Sun and above the horizon from three different latitudes on Earth.
"We see that several hundred satellites are above the horizon at all times of night; during winter twilight, and all summer night long, most of them are illuminated," writes McDowell.
Since Elon Musk’s SpaceX began launching batches of satellites in 2019, astronomers have been voicing concerns that the expanding number of huge satellite constellations, driven by Starlink's target plan of installing up to 42,000 satellites in low orbit could wreak havoc on scientific observations of space.
Both skywatchers and astronomers were shocked by the bright lights of the satellites that were obstructing the view for major telescopes and potentially corrupting between 30 to 40 percent of astronomical images.
Satellites from companies other than SpaceX, such as OneWeb pose a similar problem, as many observatories with particularly wide fields of view, like the Vera C. Rubin Observatory currently under construction in Chile, are likely to be impacted.
According to a recent study from the European Southern Observatory (ESO), satellite mega-constellations are projected as “severely” affecting between 30 and 50 percent of observations taken by the Rubin Observatory.
"However, there appear to be other science projects which may be more severely affected… For example, searches for near-Earth asteroids include observations taken in twilight, a time when the satellites are illuminated year-round," writes McDowell.
The astronomer has recently been expounding the importance of continued, unhampered observation of asteroids that may pose a danger to the Earth due to the close proximity in which they move.
When it comes to detection of near-Earth objects travelling close to the Sun, researchers typically search for them after sunset, when Starlink’s satellites illuminate the sky.
While urging additional regulation, which he claimed might help solve the issue, he stressed measures being proposed at the moment are not effective.
There has been no official comment from SpaceX.
Previously, to allay concerns, SpaceX CEO Elon Musk stated the company would work with astronomers to develop solutions to mitigate any impact on scientific observation. In response to the criticism, Elon Musk tweeted in May 2019 that the amount of light the satellites have been sending down toward Earth would be studied and measures to mitigate the effects would be taken by modifying them to be less reflective.
“Agreed, sent a note to Starlink team last week specifically regarding albedo reduction. We’ll get a better sense of value of this when satellites have raised orbits & arrays are tracking to Sun.”
Meanwhile, the company continues to launch new batches of satellites, as a Falcon 9 rocket is geared up to carry 60 more satellites to space on 18 March.
Standing down today; standard auto-abort triggered due to out of family data during engine power check. Will announce next launch date opportunity once confirmed on the Range— SpaceX (@SpaceX) March 15, 2020
SpaceX has plans to have over 1,500 satellites in space by the end of the year, with the long-term plan for the mega-constellation aiming at 42,000 satellites that would beam high-speed internet to every corner of the globe.