Using a combination of space telescope data, as well as recent data acquired with the SOFIA Airborne telescope and lab experiments, a team of astronomers including researchers from the SETI Institute and Jet Propulsion Laboratory have revealed the presence of dust of exogenic origin at the surface of dwarf planet Ceres. This contamination likely stems from a dust cloud formed in the outer part of the main belt of asteroids following a collision in recent times. That study challenges the relationship proposed between Ceres and asteroids in the C spectral class and instead suggests an origin of this dwarf planet in the transneptunian region. This study was published on January 19 2017 in Astronomical Journal.
August 31: See update at the end of this post
Several readers have contacted me recently about reports that a group of international astronomers have detected a strong signal coming from a distant star that could be a sign of a high-technology civilization. Here’s my reaction: it’s interesting, but it’s definitely not the sign of an alien civilization—at least not yet.
Here’s why: (more…)
What began as a tantalizing rumor has just become an astonishing fact. Today a group of thirty-one scientists, led by Guillem Anglada-Escude at the Queen Mary University of London, UK, announced the discovery of a terrestrial exoplanet orbiting Proxima Centauri. The discovery of this planet, Proxima Centauri b, is a huge breakthrough not just for astronomers but for all of us. Here’s why.
Another attack this month, this time in Nice in the middle of the 14 July celebrations. First, the obvious: this attack, which targeted people and families watching fireworks, was despicable and inhuman. Of course, I send my thoughts to the victims and their families as well as to my colleagues and friends who live in Nice. But I am tired of being an impotent witness to this outbreak of violence everywhere in the world, and I absolutely refuse to remain silent. Like many people, I feel like I’m living a nightmare, in a polarized world in which a tiny minority of violent sociopaths want us to embrace ideas from another time whatever the cost to us, our loved ones, our values, and our dignity as human beings. I hope that this stops and that we find a solution and learn, once and forever more, to live together in peace. But we are living in a very difficult time and we must prepare for many setbacks and tragedies.
The events in Nice also make it imperative that we learn certain key lessons. We, the citizens of free nations going about our daily business, are paying a huge price for wars launched in the first decade of this century by radical and ignorant politicians who manipulated their nations into engaging in a war without end, a war that accomplishes nothing except awakening extremism and hatred in the minds of the weak, the ignorant, and the alienated. (more…)
(87) Sylvia was discovered in 1866 by N.R. Pogson, a British astronomer located in Madras, India. This main-belt asteroid is large with a diameter of ~150 km. That’s all we knew until recently.
Another day, another video!
This time I am posting a video of the binary L5 Trojan Asteroid (617) Patroclus-Menoetius. In collaboration, with the team at the California Academy of Sciences, we have created a model of this interesting binary asteroid system which shares its orbit with Jupiter.
I finally started uploading some of the animations of the talk that I gave last month at the California Academy of Sciences. Today let’s watch (624) Hektor, the binary and bilobed largest Jupiter-Trojan asteroids. This is a puzzling multiple asteroid system with a lot of mysteries (eccentric and inclined orbit of the moon, complex shape and structure for the primary, …).
Our study based on AO observations collected over 8 years was published in 2014. The conclusion of our work is that 624 Hektor is probably a captured Kuiper-belt object and the moon formed a long time ago from the slow velocity encounter of the components.
It is official. NSF, together with scientists from Caltech, MIT and the LIGO collaboration will give an update on their effort to detect gravitational waves.
I am not going to speculate on the announcement and will simply wait for it. Joe Giaime a California Institute of Technology physicist who manages the lab and also a professor at Louisiana State University was pretty clear in the Arstechnica interview about the way this group works: “We’re really kind of old school,” he said. “We analyze our data. If there’s anything interesting we write it up in papers. We send the papers to the journals. If and only if there’s an interesting discovery that passes muster, and it has been accepted for publication by a journal, then we blab about it. Anything before that, you’re not going to get anything out of me.”
So if they indeed have detected those gravitational waves, we will also get a paper.
Below the official announcement.
I am often asked to comment on what happened in Paris last December since I have both French and American citizenships and I live in the US. Like a lot of my compatriotes, it has been difficult to watch those events unfold on Friday afternoon December 13 (I was working at George Mason University in DC ). Since then, he has been also impossible to rationalize what really happened and to give a sense on those horrific events. Today I listened to “Geopolitique”, a short program aired on France Inter which described events and their consequences in the geopolitical scale. Bernard Guetta summarized very well what are my thoughts on the Paris events and its consequences, so I decided to share with you an English translation which has been freely adapted. The French version “Comment expliquer l’inconcevable” is available on the France Inter web site.
The perpetrators of the most recent murders have no excuse whatsoever, especially not one that seeks to blame the societies they live in. Nor, for that matter, did Mohamed Merah before them, or the killers of November 13, or the killers of January 7 in Paris. They were certainly not mentally ill and they certainly were responsible for their actions — and cannot claim that the challenges of integrating into a new society make them the bloodthirsty monsters they became. (more…)
Join us tomorrow at the AGU Fall Meeting for a session on direct imaging of habitable exoplanets that I organized with my colleagues Ramses Ramirez from Cornell University and David Black.
This session consists in a discussion on the potential of new and future facilities and modeling efforts designed to detect, image and characterize habitable exoplanets, studying their formation, evolution and also the existence of possible biospheres. Topics to be covered in this session include signs of exoplanet habitability and global biosignatures that can be sought with upcoming instrumentation; instrument requirements and technologies to detect these markers; strategies for target selection and prioritization; and impacts of planetary system properties, ground-based and space telescope architectures, and impacts of instrument capabilities on the yield of potentially inhabited exoplanets.