Physical cosmology Using recent data from the Gaia spacecraft, the value of the Hubble constant is determined to be 73.52 1.62, which confirms a disagreement with other methods of measuring the constant with a confidence of 99.993%.
Volcanology A new model suggests that supervolcano eruptions occur more often in regions being pulled by tectonics.
Terror An arson attack on a pile of hay bales in the Jordan Valley does hundreds of thousands of Shekels of damage. Local authorities describe the attack as terrorist.
Abortion in the United States Iowa Governor Kim Reynolds signs a bill into law which bans most abortions in the state if a fetal heartbeat can be detected, or roughly after around six weeks into pregnancy.
Animal welfare Fifty juvenile crocodiles are seized at Heathrow Airport, London, after officials discover that they were being kept in inhumane conditions.
Cold War II The United States Navy re-establishes the United States Second Fleet, which was disbanded in 2011, citing recent heightened tensions between NATO and Russia.
2017–18 North Korea crisis U.S. President Donald Trump announces that he will meet South Korean President Moon Jae-in on May 22.
At 23:30 local time, North Korea changes its time zone to match South Korea (UTC+09:00) – a "first practical" impetus for Korean reunification, says the official North Korean agency KCNA.
Maritime incidents in 2018 A Turkish cargo ship collides with Greek warship "Armatalos" off the coast of Lesbos in the Aegean Sea. The Hellenic Navy says the ship then retreated to Turkish waters without responding to radio messages.
Jade A heap of mining waste collapses at a jade mine in Kachin State, Myanmar, causing a landslide that kills at least 17 people. Six people are also left injured and an unknown number of people are missing.
May 2018 Hawaiian volcano Kīlauea begins erupting at the Leilani Estates subdivision, spurring a mandatory evacuation order of residents.
2018 Hawaii earthquake A magnitude 6.9 earthquake hits Hawaii, the strongest in over 40 years, amid ongoing seismic and volcanic activity.
Nobel Prize in Literature The Nobel Prize in Literature 2018 is postponed to 2019 after Jean-Claude Arnault, husband of the former Swedish Academy member Katarina Frostenson, is accused of sexual assault, resulting in her resignation, and leaving the academy without a quorum.
Basque conflict Spanish Prime Minister Mariano Rajoy reminds a crowd to remember the 853 victims of the conflict and reaffirms that there will be no impunity for the violence perpetrated by ETA during its 60-year history.
In Cambo-les-Bains, France, ETA performs its final act of dissolution in the presence of politicians such as Gerry Adams, Jonathan Powell, Brian Currin and Cuauhtémoc Cárdenas.