Science Past Midnight: Space Stories for Sleep

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Tonight we follow the people who solved that puzzle. We sail with the Polynesian wayfinders who crossed the Pacific by reading stars and swells, and with the Hokule'a in 1976. We meet John Harrison and the sea clock that finally let sailors know where they were. We visit the giant dishes of the Deep Space Network in California, Spain and Australia, which listen day and night for faint whispers from far away. We ride along with Apollo 8 and Apollo 13, Mariner 4, Viking, Cassini and New Horizons on its long journey to Pluto, and we learn from the mistakes too, like the Mars Climate Orbiter and its mix-up of units. We hear how Voyager 2 was found again in 2023 after a single wrong command turned its antenna away, and how Canberra sent a gentle shout across the solar system to bring it back. And we end with the future: tiny atomic clocks and spacecraft that steer by the steady ticking of distant pulsars.

There's nothing to memorise. Lower the lights, get comfortable, and let this long, calm trip carry you off to sleep.

Sources: NASA JPL: Deep Space Network: https://www.jpl.nasa.gov/missions/dsn NASA JPL: Mission Update, Voyager 2 Communications Pause (2023): https://www.jpl.nasa.gov/news/nasa-mission-update-voyager-2-communications-pause NASA JPL: Mars Climate Orbiter: https://www.jpl.nasa.gov/missions/mars-climate-orbiter/ NASA JPL: NASA Extends Deep Space Atomic Clock Mission: https://www.jpl.nasa.gov/news/nasa-extends-deep-space-atomic-clock-mission NASA Technical Reports: SEXTANT X-ray pulsar navigation demonstration: https://ntrs.nasa.gov/citations/20180001252

#deepspace #voyager #spacetravel #astronomy #space #scienceforsleep

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Science for sleep: a slow, gentle journey from our own street to the edge of everything we can see.

The universe is about 13.8 billion years old. So how can the part we see stretch about 93 billion light years across? And why does it almost certainly carry on far beyond that, perhaps forever?

Tonight we follow a single beam of light outward, one calm step at a time: past the Moon and the Sun, past Voyager 1, now a whole light day from home, to the nearest star, across our Milky Way and on to Andromeda and the great web of galaxies. We'll meet the patient people who measured it all from here, from Henrietta Swan Leavitt's flickering stars to Edwin Hubble's discovery at Mount Wilson, and the two radio astronomers who heard the faint afterglow of the beginning. We'll look at why the edge of the observable universe is a horizon, not a wall, how many galaxies it might hold, what may lie beyond it, and how the view will slowly change in the far future.

There's nothing to memorise. Get comfortable, lower the lights, and let the universe be as big as it likes while you drift off.

Sources:

Planck Collaboration (2020) — Planck 2018 results VI: Cosmological parameters (A&A): https://doi.org/10.1051/0004-6361/201833910

Leavitt & Pickering (1912) — Periods of 25 Variable Stars in the Small Magellanic Cloud (Harvard College Observatory Circular 173): https://ui.adsabs.harvard.edu/abs/1912HarCi.173....1L

Hubble (1929) — A relation between distance and radial velocity among extra-galactic nebulae (PNAS): https://doi.org/10.1073/pnas.15.3.168

Penzias & Wilson (1965) — A Measurement of Excess Antenna Temperature at 4080 Mc/s (ApJ): https://doi.org/10.1086/148307

Conselice et al. (2016) — The Evolution of Galaxy Number Density at z < 8 (ApJ): https://doi.org/10.3847/0004-637X/830/2/83

Lauer et al. (2021) — New Horizons Observations of the Cosmic Optical Background (ApJ): https://doi.org/10.3847/1538-4357/abc881

Vardanyan, Trotta & Silk (2011) — Applications of Bayesian model averaging to the curvature and size of the Universe (MNRAS): https://arxiv.org/abs/1101.5476

DESI Collaboration (2025) — New DESI results strengthen hints that dark energy may evolve: https://newscenter.lbl.gov/2025/03/19/new-desi-results-strengthen-hints-that-dark-energy-may-evolve/

#universe #observableuniverse #space #astronomy #cosmology #scienceforsleep