Colonizing Mars Means Contaminating Mars — And Never Knowing For Sure If It Had Its Own Native Life

livescience.com – Before that happens, we need to recognize that a very real possibility exists that the first human steps on the Martian surface will lead to a collision between terrestrial life and biota native to Mars.

Source: Christopher R. Webster, et al. Background levels of methane in Mars’ atmosphere show strong seasonal variations. Science, 2018.

Jurassic marine reptile was warm-blooded, had blubber, used camouflage

upi.com – New research suggests Jurassic ichthyosaurs were more like modern marine mammals than previously realized.

Source: Johan Lindgren, et al. Soft-tissue evidence for homeothermy and crypsis in a Jurassic ichthyosaur. Nature, 2018.

Scientists find oldest evidence of black plague in 5,000-year-old human remains

zmescience.com – The remains of a 20-year-old woman found in Sweden may help scientists retrace the origin of the deadly disease.

Source: Nicolás Rascovan, et al. Emergence and Spread of Basal Lineages of Yersinia pestis during the Neolithic Decline. Cell, 2018.

Geckos’ new superpower is running on water; now we know how they do it

arstechnica.com – The mouse-sized lizards use a combination of surface tension and slapping motion.

Source: Jasmine A. Nirody, et al. Geckos Race Across the Water’s Surface Using Multiple Mechanisms. Current Biology, 2018.

Wrong way: 2018 global CO₂ emissions tick up again

arstechnica.com – More emissions from China, India, and the US.

Source: Corinne Le Quéré, et al. Global Carbon Budget 2018. Earth System Science Data, 2018.

Helium exoplanet inflates like a balloon

zmescience.com – Helium was predicted to be one of the most common elements of exoplanets, but was only recently observed for the first time.

Source: R. Allart, et al. Spectrally resolved helium absorption from the extended atmosphere of a warm Neptune-mass exoplanet. Science, 2018.

Trilobites: All the Light There is to See? 4 x 10⁸⁴ Photons.

nytimes.com – Astronomers have calculated all the light ever produced by all the stars in the cosmos. It’s a lot, but on the cosmic whole, not that much.

Source: A gamma-ray determination of the Universe’s star formation history. Science, 2018.

New experiment casts doubt on claims to have identified dark matter

digitaltrends.com – A South Korean experiment called COSINE-100 has attempted to replicate the claims of dark matter observed by the Italian DAMA/LIBRA experiment, but has failed to replicate the observations. This makes the fringe position that dark matter has already been identified more untenable.

Source: An experiment to search for dark-matter interactions using sodium iodide detectors. Nature, 2018.