The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Limits on planets around pulsating white dwarf stars

We present limits on planetary companions to pulsating white dwarf stars. A subset of these stars exhibit extreme stability in the period and phase of some of their pulsation modes; a planet can be detected around such a star by searching for periodic variations in the arrival time of these pulsations. We present limits on companions greater than a few Jupiter masses around a sample of 15 white dwarf stars as part of an ongoing survey. One star shows a variation in arrival time consistent with a 2MJ planet in a 4.5 yr orbit.We discuss other possible explanations for the observed signal and conclude that a planet is the most plausible explanation based on the data available

MOLECULAR JET SPECTROSCOPE OF SYM-TETRAZINE

Author Institution: Williams College; The James Franck Institute and The Department of Chemistry, The University of ChicagoUsing the molecular jet spectrometer of Smalley, Levy, and Wharton, several interesting observations have, been made on sym-trazine-an organic molecule of longstanding concern to spectroscopists. In particular we have observed that, while formation of van der waals’ complexes between tetrazine and the carrier gas is observed at the low effective temperatures produced in the molecular jet spectrometer, these species do not obscure the observation of tetrazine. Furthermore, these complexes form an interesting study in their own right, it is thus concluded that molecular jet spectrometry shot/s promise as a technique for studying very low rotational states of moderately large molecules in the gas phase