(CNN) The hotly contested race between Republican Roy Moore and Democrat Doug Jones will come to a close Tuesday when Alabama voters go to the polls for the special Senate election.

The big story surrounding this race is whether allegations that the 70-year-old Moore pursued sexual relationships with teenage girls -- one of whom was 14 at the time -- while in his 30s will be enough for Alabama to elect a Democrat to the seat for the first time in 25 years.

Moore, who is also known for being ousted twice as state Supreme Court chief justice, says his accusers are lying. Jones has contrasted the allegations facing Moore with his own history prosecuting two Ku Klux Klan members in the 1963 Birmingham church bombing that killed four African-American girls.

When polls close

Polls open at 8 a.m. ET and close at 8 p.m. ET.

Based on historical patterns in Alabama, nearly 70% of the vote is expected to be reported by 11 p.m. ET.

How to watch

CNN's special election coverage will begin at 5 p.m. ET on CNN and stream live for subscribers on CNNgo and the CNN mobile apps for iOS and Android.

What are the key counties?

Jefferson County is a big area to watch as it is the largest county in the state and also is home to Birmingham, the largest city in the state. It's also an area that went for incumbent Sen. Luther Strange in the Republican runoff, which occurred in September.

The suburbs of Shelby County, which neighbors Jefferson County, will also be watched closely due to the high population and the fact that Strange carried it in the runoff.

Etowah County is Moore's home county and where voters know him best. He did over perform there in the runoff, but not by much: he garnered 57% of the vote there vs. 55% overall in the state.

When will the winner join the Senate?

From the Secretary of State's office:

Per Alabama state law, results must be certified by January 3 -- 22 days from the election.

They are hopeful they will be able to certify the results sometime between December 27 and 29.

Those late December dates, however, are contingent upon all 67 counties meeting the December 22 deadline to report their results. If counties miss that deadline, it will cause problems and possibly a delay in certification.

The Senate is currently expected to adjourn for the year on December 22, after voting on the Republican tax bill and a spending bill to keep the government open.

Should Moore win, it won't change the vote calculus, which is 52 Republicans and 48 Democrats. A Jones win would mean Republicans only have a 51-49 advantage, and Democrats will be expected to demand he be seated immediately.