Brett James Gladman

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The possibility and probability of natural transfer of viable microbes from Mars to Earth and Earth to Mars traveling in meteoroids during the first 0.5 Ga and the following 4 Ga are investigated, including: --radiation protection against the galactic cosmic ray nuclei and the solar rays, dose rates as a function of the meteorite's radial column mass(More)
The giant planets in the Solar System each have two groups of satellites. The regular satellites move along nearly circular orbits in the planet's orbital plane, revolving about it in the same sense as the planet spins. In contrast, the so-called irregular satellites are generally smaller in size and are characterized by large orbits with significant(More)
Extensive collection efforts in Antarctica and the Sahara in the past 10 years have greatly increased the number of known meteorites. Groupings of meteorites according to petrologic, mineralogical, bulkchemical, and isotopic properties suggest the existence of 100–150 distinct parent bodies. Dynamical studies imply that most meteorites have their source(More)
Motivated by a desire to understand the size distribution of objects in the EdgeworthKuiper belt, an observing program has been conducted at the Palomar 5-m and CanadaFrance-Hawaii 3.6-m telescopes. We have conducted pencil-beam searches for outer solar system objects to a limiting magnitude of R ∼ 26. The fields were searched using software recombinations(More)
We calculate the current spatial distribution of projectile delivery to the Earth and Moon using numerical orbital dynamics simulations of candidate impactors drawn from a debiased Near-EarthObject (NEO) model. Surprisingly, we find that the average lunar impact velocity is 20 km/s, which has ramifications in converting observed crater densities to impactor(More)
0019-1035/$ see front matter 2009 Elsevier Inc. A doi:10.1016/j.icarus.2009.12.013 * Corresponding author. Fax: +1 617 496 6958. E-mail address: cuk@eps.harvard.edu (M. Ćuk). Multiple impact basins formed on the Moon about 3.8 Gyr ago in what is known as the lunar cataclysm or Late Heavy Bombardment. Many workers currently interpret the lunar cataclysm as(More)
Our planetary system is embedded in a small-body disk of asteroids and comets, vestigial remnants of the original planetesimal population that formed the planets. Once formed, those planets dispersed most of the remaining small bodies. Outside of Neptune, this process has left our Kuiper belt and built the Oort cloud, as well as emplacing comets into(More)