Associate Justice of the Supreme Court of the United States

Associate Justices of the Supreme Court of the United States are the members of the Supreme Court of the United States other than the Chief Justice of the United States. The number of Associate Justices is ruled by the United States Congress and is currently set at eight by the Judiciary Act of 1869.
How they are nominated.
The President "shall nominate, and by and with the Advice and Consent of the Senate, shall appoint... Judges of the supreme Court." Although the Constitution refers to them as "Judges of the Supreme Court," the title actually used is "Associate Justice," introduced in the Judiciary Act of 1789. Associate justices were traditionally styled "Mr. Justice" in court opinions, but the title was shortened to "Justice" in 1980, a year before the first female justice was appointed.
Duties.
Each of the Justices of the Supreme Court has a single vote in deciding the cases argued before it; the Chief Justice's vote counts no more than that of any other Justice.
Succession process.
Under 28 USC 3, when the Chief Justice is unable to discharge his functions, or that office is vacant, his duties are carried out by the most senior Associate Justice until the disability or the vacancy ends.
Current justices.
The current Associate Justices are (in order of seniority):