International Space Science Institute (ISSI)Hallerstrasse 6
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Phone +41 31 684 48 96

Our scientific opportunities support the community through six distinct modes of operation. Links to proposal templates or on-line submission forms are provided for each individual tool.

Find explanations, forms of applications and an overview of current and past activities.


29. June 2023

Hubble and the James Webb Space Telescope: A Tale of Two Observatories in Space

The Hubble Space Telescope has been called the most productive scientific instrument in human history. Launched in 1990, the telescope has performed observations which have measured the age of the Universe, confirmed the existence of black holes, discovered the accelerating Universe, and amazed the general public. On Christmas day in 2021 the James Webb Space Telescope (JWST) was launched into space after decades of development. JWST was designed to extend the view of Hubble in regions of the cosmos Hubble can’t penetrate. JWST is exceeding the grand expectations of its ability to unravel the mysteries of the Universe. Join Astronaut/Astrophysicist John Grunsfeld as he takes us through the stories of Hubble and Webb.

11. November 2022

Understanding the Accelerating Expansion of the Universe and the Hubble Tension

In this last year, the Pantheon+ and SH0ES teams released likely our last measurements of the expansion history of the universe.  On one hand, constraints from Pantheon+ show a universe consistent with the Lambda-CDM model, where dark energy can be described by a cosmological constant.  On the other hand, constraints combining Pantheon+SHOES data find a high value of the Hubble constant, now 5sigma away from the value inferred using Lambda-CDM from measurements of the Cosmic Microwave Background.  How can both these statements be true? In this talk, the speaker goes over these separate but overlapping measurements, and discussess how we can have tensions with some parts of the cosmological model but not others. The speaker discusses possible explanations to the Hubble tension, and goes over how other tensions have arisen in cosmology. Finally, the speaker talks about how new telescopes, like the James Webb Space Telescope, can help resolve these controversies.

A Spiral Amongst Thousands
Credits ESA/Webb, NASA & CSA, A. Martel