“A comet could stay in one place if it was basically on a ‘collision course’ with Earth,…That’s exactly what you would expect of an object that’s going to pass very, very close to the Earth.”
-Statement by Mark Matney, a planetary scientist at NASA, as quoted in Scientific American. He has proposed in his paper that the Star of Bethlehem cited in the Bible may have been a “broom star,” or comet, spotted by Chinese astronomers in 5 B.C.E. In his paper, he concludes “…it is no longer justifiable to claim that ‘no astronomical event’ could possibly have behaved in the manner described by Matthew.”
Rapidly growing satellite constellations have raised strong concerns among the scientific community. Reflections from satellites can be visible to the unaided eye and extremely bright for professional telescopes. These trails already affect astronomical images across the complete electromagnetic spectrum, with a noticeable cost for operations and mitigation efforts. Contrary to popular perception, satellite trails affect not only ground-based observatories but also space observatories such as the Hubble Space Telescope. However, the current number of satellites is only a fraction (less than 3%) of those to be launched in the next decade. Here we show a forecast of the satellite trail contamination levels for a series of international low-Earth-orbit telescopes on the basis of the proposed telecommunication industry constellations. Our results show that if these constellations are completed, one-third of the images of the Hubble Space Telescope will be contaminated, while the SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer), ARRAKIHS (Analysis of Resolved Remnants of Accreted galaxies as a Key Instrument for Halo Surveys) and Xuntian space telescopes will have more than 96% of their exposures affected, with 5.6, 69 and 92 trails per exposure, respectively, with an average surface brightness of μ = 19 ± 2 mag arcsec−2. Our results demonstrate that light contamination is a growing threat for space telescope operations. We propose a series of actions to minimize the impact of satellite constellations, allowing researchers to predict, model and correct unwanted satellite light pollution from science observations.
Image (Credit): “Land of Ice” by Kavan Chay. (darksky.org/)
This week’s image is from the Capture the Dark 2025 contest sponsored by Dark Sky International. The third place winning photo is “Land of Ice” by Kavan Chay. The photo was taken in Te Papa-Kura-o-Taranaki, New Zealand.
The 2025 contest had over 2,200 entries from over 22 countries. You can see the other winning images here.
Stay tuned for the 2026 contest, which has yet to be announced.
Image (Credit): Tenth anniversary poster for the MAVEN spacecraft from 2024. (NASA)
This time last year we were celebrating the 10th anniversary of NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft entering orbit around Mars. Today we are wondering about the future of that spacecraft after NASA lost contact with it.
As of earlier today, all NASA would say is the following:
The spacecraft and operations teams are investigating the anomaly to address the situation. More information will be shared once it becomes available.
MAVEN is part of the Mars Relay Network (MRN), which is used to transmit data from the Martian surface back to Earth. For instance, NASA’s two remaining rovers – Curiosity and Perseverance – utilize this network. Five NASA and European Space Agency spacecraft orbiting Mars are part of the MRN: MAVEN, Mars Odyssey, Mars Express, Mars Reconnaissance Orbiter, and ExoMars Trace Gas Orbiter.
The last thing we need now under this administration is a weak link to Mars since finding funds to further bolster the MRN will not be easy. So let’s hope for an easy fix.
Our Awesome Universe 