On my way to Florida for a podcast interview with the visionary Matt Beall, I received an email from the Founder and CEO of LifeShip, Ben Halderman, who wrote:
“Dear Avi,
Hope you’re doing great! I wanted to share some exciting news. LifeShip is heading to an asteroid! Is there something that makes sense to send to an asteroid together?
We do have a short time before manufacturing the storage archives and delivering our payload in July. This mission is unique. It will be the first ever commercial mission and first monument on an asteroid. Let me know if you want to be part of it.
Together to the stars!
Ben”
LifeShip aims to preserve life, art and stories of humanity in space for eternity. Keeping humanity’s artifacts on the Moon will not fulfil this goal, because within 7.6 billion years the Sun will expand and its red giant envelope will engulf the Earth and the Moon. Owing to friction on the surrounding gas, the Moon will ultimately crash on Earth and Earth will sink towards the Sun’s core and get evaporated. However, an asteroid on a sufficiently extended orbit could avoid this devastating death. Coincidentally, I received a second email around the same time from 13-year-old teenager in Baku, Azerbaijan, who wondered whether death is unavoidable and part of a deeper plan in the Universe. I rushed to explain that there is no such plan and that our future can be shaped by our desire to gain immortality. In reply to Ben, I wrote:
“Wonderful to hear about the asteroid mission, Ben. If I had an opportunity to decorate an asteroid, I would send a pulsing laser with an accurate timer. The detection of the pulses on Earth would allow us to measure the motion of the asteroid relative to Earth to an exquisite precision and test Einstein’s theory of gravity.
If a transmitter is too expensive, I would place retroreflectors on the asteroid. In 1969, Apollo 11 astronauts placed the first corner-cube retroreflectors on the lunar surface. These retroreflectors reflect light back with minimum losses. Over the past half century, the lunar retroreflectors were used to measure the travel time of laser pulses from a telescope on Earth to the Moon and back. Currently, there are five reflector arrays on the Moon — three deployed by Apollo astronauts and two on Soviet rovers. The distance to the Moon is currently measured to a precision of a few millimeters, leading to unprecedented limits on the time dependence of Newton’s constant or deviations from the equivalence principle.
Laser ranging of an asteroid could also probe the transient gravitational effect of passing dark matter clumps on the Earth-asteroid distance, as I discussed in a recent paper.
Let me know if the above is feasible. Sorry for thinking like a physicist and not like a poet, but I cannot resist the temptation of pointing out that this could be an exciting opportunity for fundamental physics.
Avi”
Ben responded:
“Hi Avi. A retroreflector or laser would be an exciting experiment. For this mission we have a small passive payload inside the spacecraft.
I guess our partners and customers on this are more likely poets and artists than scientists 🙂
Best!
Ben”
In response, I wrote:
“Well, sending a piece of art would be worthwhile in case there is an audience to witness it. If a tree falls in a forest and no one is around to hear it, does it make a sound? I am afraid that the only audience in the foreseeable future would be on Earth. A retroreflector is a passive object. Is it possible to deliver it to the surface of the asteroid?”
Ben noted:
“It is probably possible to add a retroreflector on the spacecraft. But I’d need a budget for it as it would be a separate payload. Is there funding that we could access for it? There is only about a month and a half to add content to the mission so we likely don’t have time to apply for grants.”
and so, I asked:
“How much will it cost? The only possibility I can think of is private donors.”
to which Ben replied:
“A recent mission to the Moon had a 20g retroreflector on it. Let’s say about $1k per gram for launch cost and some to go towards LifeShip for the mission.
We may need a bigger retroreflector since this is much further away. So, there is likely something that we could do for around $25k. Or if we need a much bigger retroreflector then it may need to be $50k or $100k.”
If anyone reading this essay would like to support this scientific mission, please let Ben or me know.
Two decades ago, I discussed with my Princeton colleague, Ed Turner, the feasibility of detecting bright flares from retroreflectors as a technological signature of extraterrestrial civilizations. Such technological structures would reflect light from the host star far more effectively than natural objects of the same size. They would flare in brightness whenever they reach favorable orientations relative to the star and Earth. Here’s hoping that other civilizations in our cosmic neighborhood are more ambitious than we are in decorating their asteroids with huge retroreflectors.
ABOUT THE AUTHOR
Avi Loeb is the head of the Galileo Project, founding director of Harvard University’s — Black Hole Initiative, director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics, and the former chair of the astronomy department at Harvard University (2011–2020). He is a former member of the President’s Council of Advisors on Science and Technology and a former chair of the Board on Physics and Astronomy of the National Academies. He is the bestselling author of “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth” and a co-author of the textbook “Life in the Cosmos”, both published in 2021. The paperback edition of his new book, titled “Interstellar”, was published in August 2024.
