Comparison of Fishes Occurring in Alga and Seagrass Habitats on the East Coast of Florida

I compare the distribution and abundance of fishes between macroalga and seagrass habitats in Indian River lagoon, Florida. I sampled fishes monthly (Oct. 1986 - Sept. 1987) for a year by placing seines 10 m apart and pulling them together. I used a 1 m2 throw net to sample during March, May, June, August and September 1987. There was no significant difference in temperature, salinity, dissolved oxygen, and pH between habitats. Water depth was significantly different between alga (mean = 0.80 m) and seagrass (mean = 0.52 m). Dominate species (Lucania parva, Menidia peninsulae, Gobiosoma robustum, Syngnathus scovelli, Microgobius gulosus, Eucinostomus lefroyi, Floridichthys carpio, and Strongylura notata) were similar between the two habitats. Mean abundance, biomass, juvenile abundance and richness per seine tow; and abundance and biomass per throw net throw were significantly greater for sea grass habitat (p \u3c0.05). Multiple regression analysis indicated that habitat type accounted for the majority of the variation in abundance (37%) and biomass of fishes (31%) collected. Vegetation biomass, dissolved oxygen, pH, salinity, temperature, and water depth accounted for smaller amounts (\u3c10%) of variation in abundance and biomass of fishes

In-Space Utilisation of Asteroids::“Answers to Questions from the Asteroid Miners”

The aim of the Asteroid Science Intersections with In-­Space Mine Engineering (ASIME) 2016 conference on September 21-­‐22, 2016 in Luxembourg City wasto provide an environment for the detailed discussion of the specific properties of asteroids, with the engineering needs of space missions that utilize asteroids.The ASIME 2016 Conference produced a layered record of discussions from theasteroid scientists and the asteroid miners to understand each other’s key concerns and to address key scientific questions from the asteroid mining companies: Planetary Resources, Deep Space Industries and TransAstra. These Questions were the focus of the two day conference, were addressed byscientists inside and outside of the ASIME Conference and are the focus ofthis White Paper.The Questions from the asteroid mining companies have been sorted into the three asteroid science themes: 1) survey, 2) surface and 3) subsurface and 4)Other. The answers to those Questions have been provided by the scientists with their conference presentations or edited directly into an early open-­‐access collaborative Google document (August 2016-­‐October 2016), or inserted byA. Graps using additional reference materials. During the ASIME 2016 last two-­‐hours, the scientists turned the Questions from the Asteroid Miners around by presenting their own key concerns: Questions from the Asteroid Scientists. These answers in this White Paper will point to the Science Knowledge Gaps (SKGs) for advancing the asteroid in-­‐space resource utilisation domain

Achievement of the planetary defense investigations of the Double Asteroid Redirection Test (DART) mission

NASA's Double Asteroid Redirection Test (DART) mission was the first to demonstrate asteroid deflection, and the mission's Level 1 requirements guided its planetary defense investigations. Here, we summarize DART's achievement of those requirements. On 2022 September 26, the DART spacecraft impacted Dimorphos, the secondary member of the Didymos near-Earth asteroid binary system, demonstrating an autonomously navigated kinetic impact into an asteroid with limited prior knowledge for planetary defense. Months of subsequent Earth-based observations showed that the binary orbital period was changed by –33.24 minutes, with two independent analysis methods each reporting a 1σ uncertainty of 1.4 s. Dynamical models determined that the momentum enhancement factor, β, resulting from DART's kinetic impact test is between 2.4 and 4.9, depending on the mass of Dimorphos, which remains the largest source of uncertainty. Over five dozen telescopes across the globe and in space, along with the Light Italian CubeSat for Imaging of Asteroids, have contributed to DART's investigations. These combined investigations have addressed topics related to the ejecta, dynamics, impact event, and properties of both asteroids in the binary system. A year following DART's successful impact into Dimorphos, the mission has achieved its planetary defense requirements, although work to further understand DART's kinetic impact test and the Didymos system will continue. In particular, ESA's Hera mission is planned to perform extensive measurements in 2027 during its rendezvous with the Didymos–Dimorphos system, building on DART to advance our knowledge and continue the ongoing international collaboration for planetary defense