1963: Arecibo Ionospheric Observatory Commissioned for service on November 1 for $9.7 million. 1965: One of its first accomplishments was establishing the rotation rate of Mercury, which turned out to be 59 days rather than the previously estimated 88 days. 1968: Sporadic radio pulses from the direction of the Crab Nebula supernova remnant found at Green … Read more
1963: Arecibo Ionospheric Observatory Commissioned for service on November 1 for $9.7 million. 1965: One of its first accomplishments was establishing the rotation rate of Mercury, which turned out to be 59 days rather than the previously estimated 88 days. 1968: Sporadic radio pulses from the direction of the Crab Nebula supernova remnant found at Green … Read more
1963: Arecibo Ionospheric Observatory Commissioned for service on November 1 for $9.7 million. 1965: One of its first accomplishments was establishing the rotation rate of Mercury, which turned out to be 59 days rather than the previously estimated 88 days. 1968: Sporadic radio pulses from the direction of the Crab Nebula supernova remnant found at Green … Read more
1963: Arecibo Ionospheric Observatory Commissioned for service on November 1 for $9.7 million. 1965: One of its first accomplishments was establishing the rotation rate of Mercury, which turned out to be 59 days rather than the previously estimated 88 days. 1968: Sporadic radio pulses from the direction of the Crab Nebula supernova remnant found at Green … Read more