The James Webb Space Telescope detects CO2 in an exoplanet’s atmosphere for the first time

This is WASP-39b, an exoplanet located 700 light years from Earth. Its peculiarity is that of being a “hot Jupiter” that is a gaseous planet of over 1000°C. A high temperature that expands its atmosphere and simply makes it easier to observe. This is one of the features that make WASP-39b a model for studying the atmospheric composition of exoplanets. We are therefore testing some observations on it, before tackling small rocky planets.

To determine the composition of its atmosphere, the researchers here use the so-called “transit” method, i.e. the planet will pass in front of its star, and by studying the light filtered by its star, we can trace the atmospheric composition. In this case, this exoplanet passes in front of its star every four days! This consortium of 150 researchers thus observed the planet passing four times in front of its star, with four different instruments, to observe different wavelengths in the near infrared and thus detect different chemical elements.

Results, six different chemical species have been identified: water, already observed by Hubble, carbon monoxide, potassium, sodium but above all carbon dioxide. This is the first time we see it! And second surprise, sulfur dioxide, which testifies to photochemistry, ie the chemistry initiated by the radiation of the star, a phenomenon which on Earth has allowed the formation of the ozone layer, and therefore indirectly, of life. These findings are published in five new studies to be published in Nature (

1 ,

2 ,

3 ,

4 and of

5)

Interview with Vivien Parmentier, junior professor at the Lagrange Laboratory of the University of the Côte d’Azur and co-author of the 5 new studies

Wolves infected with some parasites are more likely to become pack leaders

The parasite in question is Toxoplasma gondii, which causes toxoplasmosis. We know that this parasite is transmitted to wolves by eating contaminated prey such as pumas or cats. We already knew its effect on the behavior of rats, for example, which when infected are less afraid of their predator, cats. This constitutes an “advantage” for the parasite, because by making its host less fearful and more adventurous, it increases its chances of being ingested by another animal and therefore has a better chance of spreading.

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University of Montana researchers he wanted to study whether this infection caused similar changes in gray wolves. They tracked nearly 230 Yellowstone Park wolves over nearly 27 years. They took blood samples to check for infections and correlated the number of infections with their family history and social status.

And it turns out that infected wolves were eleven times more likely than uninfected wolves to abandon their birth family and start a new one, and 46 times more likely to become pack leaders. The authors therefore believe that, like rats, their behavior in infected wolves is modified by the parasite. They also speculate that in the past, wolves would have been more likely to be eaten by American lions, their predatory panther family that disappeared from the region 11,000 years ago.

To combat parasites, some birds resort to self-medication

There is a bit of anthropomorphism in talking about self-medication, but clearly some animals would tend to turn to certain plants for protection. Here we are interested in the bustard whose males are particularly prone to parasitic infections during the breeding season.

Researchers from the National Museum of Natural Sciences of Spain they collected the droppings of these birds, more than a quarter of which came from the breeding season. It turns out that males are more likely to feed on two plants during mating season: poppies and bugloss, plants that contain chemical compounds with antiparasitic effects in vitro, in the laboratory. So this is not really proof, but rather a potential clue to the use of plants for their medicinal properties by animals. Because we don’t know how bustards spot them, or what their real effects are on their immune systems.

The birth of the biggest children in the world

This is the nickname of these twins, Lydia and Timothy, born almost a month ago in the United States, on October 31st, but conceived in April 1992. They were therefore born from frozen embryos over 30 years old. This is a record so far. Like all embryos, they were “manufactured” then frozen in liquid nitrogen at -200°C… Usually this cryopreservation is limited to 5 or 10 years… but we know that freezing does not alter the quality of the cells of the embryos for at least three decades , which is the case here.

Thanks to Vivien Parmentier for her precious explanations

For further

The five studies on the atmospheric composition of WASP-39b (

1,

2,

3,

4and of

5soon to be published in Nature)

The James Webb Space Telescope immerses us in the atmosphere of this exoplanet (Number)

The study on the behavior change of wolves when they are infected (Nature, in English)

The parasite gives wolves what it takes to be pack leaders (Nature, in English)

Like us, the bustard may resort to self-medication (Science and future)

Birth of the “biggest children in the world” (Scientific Mail)