As the “Asteroid Day” PR machine is shifting into high gear, let me add some clarity to the buzz. While I’m semi-retired, I’m still doing some consulting work for NASA’s Planetary Defense Coordination Office, which encompasses NASA’s Near Earth Object (NEO) Observations Program. The NEO Observations Program funds projects to find, track, and characterize asteroids and identify those that pose a risk of impact with Earth. These NASA-funded projects account for well over 90 percent of NEO detections. No one asked me to write this post.
Asteroid Day, if you’re not already familiar with it, is an annual event that first took place in 2015. A small group of people including two ex-NASA astronauts, a rock-guitarist/scientist, and a science-fiction filmmaker got together a few years back to come up with a way to raise awareness of the hazard of asteroid impacts with Earth. They declared June 30 – the day of the 1908 Tunguska, Siberia, impact event – “Asteroid Day,” and they organized some highly publicized public events to take place on that date. Their first “Asteroid Day” was June 30, 2015. The Asteroid Day team pulled together some big names in science and entertainment and a slew of ex-astronauts and cosmonauts to draw public attention to their cause.
Those events, and the publicity campaign leading up to them, raised some concerns, for me and some of my colleagues in planetary defense. The group’s rhetoric was alarmist – take for example, this quote from AD co-founder Brian May (yes, that Brian May): “The more we learn about asteroid impacts, the clearer it became that the human race has been living on borrowed time… Asteroid Day and the 100X Declaration are ways for the public to contribute to an awareness of the Earth’s vulnerability and the realization that Asteroids hit Earth all the time. Asteroid Day would the vehicle to garner public support to increase our knowledge of when asteroids might strike and how we can protect ourselves.”
The 100X Declaration, calling for “A rapid hundred-fold (100x) acceleration of the discovery and tracking of Near-Earth Asteroids to 100,000 per year within the next ten years,” was a concern as well. People who were (and are) actually engaged in the endeavor of in finding, tracking, and characterizing asteroids told me that no matter how much money might be invested in the endeavor (money that is not, by the way, available), such a goal would be unachievable.
Members of the planetary defense community – including myself – have been in communication with the Asteroid Day team since June 30, 2015, trying to improve the accuracy of their communications. To their credit, they have been doing so.
For example, this is what the Asteroid Day team now has to say about their 100X Declaration: “The 100x is an aspirational goal. Current asteroid survey projects are finding about 1500 asteroids per year that can come near the Earth. It is not likely that we will detect 100 times this number of asteroids per year with our current capabilities.”
I found this content on the Asteroid Day web site preceding June 30, 2015: “Continuing to orbit our solar system without the knowledge of potentially dangerous asteroids in our orbital neighbourhood is equivalent to playing the odds in a game of Las Vegas roulette – only this time, we are betting our families, homes and indeed future generations. The probability of Earth being impacted in a random location by a 100-megaton asteroid in your lifetime is about the same as the probability of you being killed in an automobile accident. These odds on any individual day are small, yet few among us would drive a car without wearing a seat belt. The 100x Asteroid Declaration calls for the discovery and tracking of 100,000 asteroids a year over the next ten years. In addition to protecting our planet, this increased capability will provide dramatically improved knowledge of our Solar System for scientific and other purposes.”
It no longer appears on the web site.
The sort of language that I call “alarmist” still appears on the AD web site here and there. For example, on a page called “asteroid basics,” you’ll see references to “the threat from asteroids” and “the cosmic shooting gallery.”
But overall, the AD crew has toned down the “threat” rhetoric and improved the clarity, accuracy, and comprehensiveness of the information it provides on what we know about the asteroid population and how we find, track and characterize asteroids and identify those that the experts deem “potentially hazardous.” Many thanks to them and especially to all the experts in the NEO science/planetary defense community, most of them funded by NASA or the European Space Agency, who contributed their expertise to this endeavor.
Despite this progress, the mass media love talk of threats and danger, and at least one scientist involved in Asteroid Day 2017 appears to have taken advantage of that proclivity.
A press release put out by Queen’s University-Belfast on June 20 has garnered some attention with its headline, “QUEEN’S UNIVERSITY SCIENTIST WARNS OF ASTEROID DANGER: A leading astrophysicist from Queen’s University Belfast has warned that an asteroid strike is just a matter of time.” The release leads off: “Fitzsimmons…has said it is a case of when an asteroid collision will happen, rather than if it will happen. Joined by…astronauts such as Apollo 9 astronaut Rusty Schweickart…Fitzsimmons is highlighting the threat for Asteroid Day, a global event next Friday (30 June).”
Fitzsimmons does note, after sounding the alarm, that “scientists and engineers have made great strides in detecting Near-Earth Asteroids and understanding the threat posed by them. Over 1,800 potentially hazardous objects have been discovered so far, but there are many more waiting to be found. Astronomers find Near-Earth Asteroids every day and most are harmless. But it is still possible the next Tunguska would take us by surprise, and although we are much better at finding larger asteroids, that does us no good if we are not prepared to do something about them.”
On June 23, Fox News (among other media outlets) reported on this release: “Earth could be hit by surprise asteroid strike, expert warns.”
I wonder about the intended purpose of this alarmist rhetoric. Is it to draw attention to an individual or institution? If so, it works. Is it to scare people? If so, for shame… Is it – as some propagators of this rhetoric have claimed – to prod governments to invest more money in asteroid detection and planetary defense? If so, it isn’t working.
Here are some everyday-English definitions of some key terms that I recommend:
- Hazard: potential to cause harm.
- Risk: assessment of probability and extent of harm.
- Threat: a declaration of an intention or determination to inflict punishment, injury, etc., in retaliation for, or conditionally upon, some action or course. (LB note: asteroids are inanimate objects. They have no intent.)
Here’s my answer to the question: what is the risk of an asteroid impact with Earth?
“Risk” is a subjective concept. For scientists who study near-Earth asteroids – or near-Earth objects (NEOs) – “risk” is a mathematical calculation. Based on known orbits of a NEO around the Sun, scientists can calculate the future orbital movements of the object and mathematically predict possible close approaches to or impacts with Earth over the next 100 years. These mathematical predictions are couched in considerable uncertainty. As scientists observe more orbits of a NEO, they can gradually reduce the uncertainty surrounding earlier predictions. Once they collect sufficient data on the object, they will be able to either confirm that an impact will occur on a specific date or eliminate the risk of impact.
Another point of clarity: Asteroid Day is not the same thing as International Asteroid Day. On December 6, 2016, the United Nations General Assembly approved a resolution declaring June 30 annually to be International Asteroid Day, “to raise public awareness about the asteroid impact hazard…. International Asteroid Day will encourage reflection on the impact hazard of asteroids and the global work undertaken in this area and facilitated by UNOOSA, including work by the Committee on the Peaceful Uses of Outer Space (COPUOS) and its Member States, the Space Mission Planning Advisory Group, and the International Asteroid Warning Network. All United Nations Member States, organizations of the United Nations system, other international and regional organizations, as well as civil society, including non-governmental organizations and individuals, are invited to observe International Asteroid Day. The UNGA’s decision was made after a proposal by the Association of Space Explorers, which was endorsed by COPUOS.”
Additional points of clarity:
- The proposal by the Association of Space Explorers was spearheaded by ex-NASA astronauts Rusty Schweickart and Ed Lu. At the time that they were pushing their proposal to the U.N., they also were engaged in fundraising for their B612 Foundation, which proposed to build and launch a space-based NEO survey telescope, which they called Sentinel. It’s not clear from B612’s “mission” web page whether Sentinel is moving ahead or not.
- Meanwhile, B612 has partnered with the Large Synoptic Survey Telescope (LSST) project to work on asteroid detection. Steve Chesley and Peter Veres of the Jet Propulsion Laboratory’s Center for NEO Studies (funded by the PDCO) have published the results of a two-year study of the projected NEO discovery performance of the LSST. Their paper (JPL Publication 16-11, April 2017) is available on arxiv.org.
- Danica Remy, co-founder of Asteroid Day, is president of B612. Brian May (yes, that Brian May), is a “strategic advisor” to B612.
- Neither B612 nor Asteroid Day is participating in the Space Missions Planning Advisory Group or the International Asteroid Warning Network. SMPAG and IAWN are comprised, respectively, of government agencies involved in designing and building space missions and government agencies and other research institutions engaged in the work of finding, tracking, and characterizing asteroids.
NASA is not a partner in Asteroid Day, but it is producing an hour of television programming to be aired for Asteroid Day on Friday. This programming will feature researchers funded by NASA as well as some amateur astronomers who are doing the work of finding, tracking, and characterizing asteroids and planning for planetary defense. You can watch this programming on NASA TV.